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Quantity Quotes (136 quotes)

’Tis evident, that as common Air when reduc’d to half Its wonted extent, obtained near about twice as forcible a Spring as it had before; so this thus- comprest Air being further thrust into half this narrow room, obtained thereby a Spring about as strong again as that It last had, and consequently four times as strong as that of the common Air. And there is no cause to doubt, that If we had been here furnisht with a greater quantity of Quicksilver and a very long Tube, we might by a further compression of the included Air have made It counter-balance “the pressure” of a far taller and heavier Cylinder of Mercury. For no man perhaps yet knows how near to an infinite compression the Air may be capable of, If the compressing force be competently increast.
A Defense of the Doctrine Touching the Spring and Weight of the Air (1662), 62.
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“Conservation” (the conservation law) means this … that there is a number, which you can calculate, at one moment—and as nature undergoes its multitude of changes, this number doesn't change. That is, if you calculate again, this quantity, it'll be the same as it was before. An example is the conservation of energy: there's a quantity that you can calculate according to a certain rule, and it comes out the same answer after, no matter what happens, happens.
'The Great Conservation Principles', The Messenger Series of Lectures, No. 3, Cornell University, 1964. From transcript of BBC programme (11 Dec 1964).
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“Science studies everything,” say the scientists. But, really, everything is too much. Everything is an infinite quantity of objects; it is impossible at one and the same time to study all. As a lantern cannot light up everything, but only lights up the place on which it is turned or the direction in which the man carrying it is walking, so also science cannot study everything, but inevitably only studies that to which its attention is directed. And as a lantern lights up most strongly the place nearest to it, and less and less strongly objects that are more and more remote from it, and does not at all light up those things its light does not reach, so also human science, of whatever kind, has always studied and still studies most carefully what seems most important to the investigators, less carefully what seems to them less important, and quite neglects the whole remaining infinite quantity of objects. ... But men of science to-day ... have formed for themselves a theory of “science for science's sake,” according to which science is to study not what mankind needs, but everything.
In 'Modern Science', Essays and Letters (1903), 223.
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[Helmholtz] is not a philosopher in the exclusive sense, as Kant, Hegel, Mansel are philosophers, but one who prosecutes physics and physiology, and acquires therein not only skill in developing any desideratum, but wisdom to know what are the desiderata, e.g., he was one of the first, and is one of the most active, preachers of the doctrine that since all kinds of energy are convertible, the first aim of science at this time. should be to ascertain in what way particular forms of energy can be converted into each other, and what are the equivalent quantities of the two forms of energy.
Letter to Lewis Campbell (21 Apr 1862). In P.M. Harman (ed.), The Scientific Letters and Papers of James Clerk Maxwell (1990), Vol. 1, 711.
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[In early mill designs, from repeated handling, the flour was mixed with a] great quantity of dirt … from the dirty feet of every one who trampled in it, trailing it over the whole Mill and wasting much … [for] people did not even then like to eat dirt, if they could see it.
As quoted in Dave DeWitt, The Founding Foodies: How Washington, Jefferson, and Franklin Revolutionized American Cuisine (2010), 82. Shorter quote cited in Carroll Pursell, The Machine in America: A Social History of Technology (1995), Notes, 322, as being quoted from Greeville and Dorothy Bathe, Oliver Evans: A Chronicle of Early American Engineering (1935), 12.
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[Mathematics is] the study of the measurement, properties, and relationships of quantities and sets, using numbers and symbols.
Definition of Mathematics in William morris (ed.), American Heritage Dictionary (2000).
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Question: If you were to pour a pound of molten lead and a pound of molten iron, each at the temperature of its melting point, upon two blocks of ice, which would melt the most ice, and why?
Answer: This question relates to diathermancy. Iron is said to be a diathermanous body (from dia, through, and thermo, I heat), meaning that it gets heated through and through, and accordingly contains a large quantity of real heat. Lead is said to be an athermanous body (from a, privative, and thermo, I heat), meaning that it gets heated secretly or in a latent manner. Hence the answer to this question depends on which will get the best of it, the real heat of the iron or the latent heat of the lead. Probably the iron will smite furthest into the ice, as molten iron is white and glowing, while melted lead is dull.
Genuine student answer* to an Acoustics, Light and Heat paper (1880), Science and Art Department, South Kensington, London, collected by Prof. Oliver Lodge. Quoted in Henry B. Wheatley, Literary Blunders (1893), 180-1, Question 14. (*From a collection in which Answers are not given verbatim et literatim, and some instances may combine several students' blunders.)
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Question: Why do the inhabitants of cold climates eat fat? How would you find experimentally the relative quantities of heat given off when equal weights of sulphur, phosphorus, and carbon are thoroughly burned?
Answer: An inhabitant of cold climates (called Frigid Zoans) eats fat principally because he can't get no lean, also because he wants to rise is temperature. But if equal weights of sulphur phosphorus and carbon are burned in his neighbourhood he will give off eating quite so much. The relative quantities of eat given off will depend upon how much sulphur etc. is burnt and how near it is burned to him. If I knew these facts it would be an easy sum to find the answer.
Genuine student answer* to an Acoustics, Light and Heat paper (1880), Science and Art Department, South Kensington, London, collected by Prof. Oliver Lodge. Quoted in Henry B. Wheatley, Literary Blunders (1893), 183, Question 32. (*From a collection in which Answers are not given verbatim et literatim, and some instances may combine several students' blunders.)
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3 Kegs Senica oil 50 Dllrs.
[One of the earliest U.S. documents recording a quantity of petroleum with its price, also shown in pounds and shillings as L56. 5s.]
Day book entry (Nov 1797). John E. Reynolds Collection, Crawford Historical Society, Meadville, Pennsylvania. Cited in Drake Well Foundation, Oil Industry History (2000), Vols 1-5, 23. Seneca Indians for centuries had cribbed oil seeps to collect petroleum for various uses, and trading. (It was not until 27 Aug 1859 that the world's first oil well was drilled in Titusville, PA.)
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A manure containing several ingredients acts in this wise: The effect of all of them in the soil accommodates itself to that one among them which, in comparison to the wants of the plant, is present in the smallest quantity.
'Laws of Minimum', in Natural Laws of Husbandry (1863), 215.
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A nation has a fixed quantity of invention, and it will make itself felt.
Endymion (1880), 195.
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About eight days ago I discovered that sulfur in burning, far from losing weight, on the contrary, gains it; it is the same with phosphorus; this increase of weight arises from a prodigious quantity of air that is fixed during combustion and combines with the vapors. This discovery, which I have established by experiments, that I regard as decisive, has led me to think that what is observed in the combustion of sulfur and phosphorus may well take place in the case of all substances that gain in weight by combustion and calcination; and I am persuaded that the increase in weight of metallic calxes is due to the same cause... This discovery seems to me one of the most interesting that has been made since Stahl and since it is difficult not to disclose something inadvertently in conversation with friends that could lead to the truth I have thought it necessary to make the present deposit to the Secretary of the Academy to await the time I make my experiments public.
Sealed note deposited with the Secretary of the French Academy 1 Nov 1772. Oeuvres de Lavoisier, Correspondance, Fasc. II. 1770-75 (1957), 389-90. Adapted from translation by A. N. Meldrum, The Eighteenth-Century Revolution in Science (1930), 3.
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According to Democritus, atoms had lost the qualities like colour, taste, etc., they only occupied space, but geometrical assertions about atoms were admissible and required no further analysis. In modern physics, atoms lose this last property, they possess geometrical qualities in no higher degree than colour, taste, etc. The atom of modern physics can only be symbolized by a partial differential equation in an abstract multidimensional space. Only the experiment of an observer forces the atom to indicate a position, a colour and a quantity of heat. All the qualities of the atom of modern physics are derived, it has no immediate and direct physical properties at all, i.e. every type of visual conception we might wish to design is, eo ipso, faulty. An understanding of 'the first order' is, I would almost say by definition, impossible for the world of atoms.
Philosophic Problems of Nuclear Science, trans. F. C. Hayes (1952), 38.
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Astronomers and physicists, dealing habitually with objects and quantities far beyond the reach of the senses, even with the aid of the most powerful aids that ingenuity has been able to devise, tend almost inevitably to fall into the ways of thinking of men dealing with objects and quantities that do not exist at all, e.g., theologians and metaphysicians. Thus their speculations tend almost inevitably to depart from the field of true science, which is that of precise observation, and to become mere soaring in the empyrean. The process works backward, too. That is to say, their reports of what they pretend actually to see are often very unreliable. It is thus no wonder that, of all men of science, they are the most given to flirting with theology. Nor is it remarkable that, in the popular belief, most astronomers end by losing their minds.
Minority Report: H. L. Mencken’s Notebooks (1956), Sample 74, 60.
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Astronomy affords the most extensive example of the connection of physical sciences. In it are combined the sciences of number and quantity, or rest and motion. In it we perceive the operation of a force which is mixed up with everything that exists in the heavens or on earth; which pervades every atom, rules the motion of animate and inanimate beings, and is a sensible in the descent of the rain-drop as in the falls of Niagara; in the weight of the air, as in the periods of the moon.
On the Connexion of the Physical Sciences (1858), 1.
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Ax: 100 Every thing doth naturally persevere in yt state in wch it is unlesse it bee interrupted by some externall cause, hence… [a] body once moved will always keepe ye same celerity, quantity & determination of its motion.
Newton’s 'Waste Book' (1665). Quoted in Richard Westfall, Never at Rest: A Biography of Isaac Newton (1980), 145.
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Besides accustoming the student to demand, complete proof, and to know when he has not obtained it, mathematical studies are of immense benefit to his education by habituating him to precision. It is one of the peculiar excellencies of mathematical discipline, that the mathematician is never satisfied with à peu près. He requires the exact truth. Hardly any of the non-mathematical sciences, except chemistry, has this advantage. One of the commonest modes of loose thought, and sources of error both in opinion and in practice, is to overlook the importance of quantities. Mathematicians and chemists are taught by the whole course of their studies, that the most fundamental difference of quality depends on some very slight difference in proportional quantity; and that from the qualities of the influencing elements, without careful attention to their quantities, false expectation would constantly be formed as to the very nature and essential character of the result produced.
In An Examination of Sir William Hamilton’s Philosophy (1878), 611. [The French phrase, à peu près means “approximately”. —Webmaster]
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But in the heavens we discover by their light, and by their light alone, stars so distant from each other that no material thing can ever have passed from one to another; and yet this light, which is to us the sole evidence of the existence of these distant worlds, tells us also that each of them is built up of molecules of the same kinds as those which we find on earth. A molecule of hydrogen, for example, whether in Sirius or in Arcturus, executes its vibrations in precisely the same time. Each molecule, therefore, throughout the universe, bears impressed on it the stamp of a metric system as distinctly as does the metre of the Archives at Paris, or the double royal cubit of the Temple of Karnac ... the exact quantity of each molecule to all others of same kind gives it, as Sir John Herschel has well said, the essential character of a manufactured article and precludes the idea of its being external and self-existent.
'Molecules', 1873. In W. D. Niven (ed.), The Scientific Papers of James Clerk Maxwell (1890), Vol. 2, 375-6.
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But just as much as it is easy to find the differential of a given quantity, so it is difficult to find the integral of a given differential. Moreover, sometimes we cannot say with certainty whether the integral of a given quantity can be found or not.
Webmaster has looked and found no citation, and no example, in books with this wording, earlier than in a list of quotes, without citation, in Baumslag Benjamin, Fundamentals Of Teaching Mathematics At University Level (2000), 214. The original would be in native French, so different translations are possible. Can you help?
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Children are told that an apple fell on Isaac Newton’s head and he was led to state the law of gravity. This, of course, is pure foolishness. What Newton discovered was that any two particles in the universe attract each other with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them. This is not learned from a falling apple, but by observing quantities of data and developing a mathematical theory that can be verified by additional data. Data gathered by Galileo on falling bodies and by Johannes Kepler on motions of the planets were invaluable aids to Newton. Unfortunately, such false impressions about science are not universally outgrown like the Santa Claus myth, and some people who don’t study much science go to their graves thinking that the human race took until the mid-seventeenth century to notice that objects fall.
In How to Tell the Liars from the Statisticians (1983), 127.
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Compare ... the various quantities of the same element contained in the molecule of the free substance and in those of all its different compounds and you will not be able to escape the following law: The different quantities of the same element contained in different molecules are all whole multiples of one and the same quantity, which always being entire, has the right to be called an atom.
Sketch of a Course of Chemical Philosophy (1858), Alembic Club Reprint (1910), 11.
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Electric and magnetic forces. May they live for ever, and never be forgot, if only to remind us that the science of electromagnetics, in spite of the abstract nature of its theory, involving quantities whose nature is entirely unknown at the present, is really and truly founded on the observations of real Newtonian forces, electric and magnetic respectively.
From 'Electromagnetic Theory, CXII', The Electrician (23 Feb 1900), Vol. 44, 615.
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England and all civilised nations stand in deadly peril of not having enough to eat. As mouths multiply, food resources dwindle. Land is a limited quantity, and the land that will grow wheat is absolutely dependent on difficult and capricious natural phenomena... I hope to point a way out of the colossal dilemma. It is the chemist who must come to the rescue of the threatened communities. It is through the laboratory that starvation may ultimately be turned into plenty... The fixation of atmospheric nitrogen is one of the great discoveries, awaiting the genius of chemists.
Presidential Address to the British Association for the Advancement of Science 1898. Published in Chemical News, 1898, 78, 125.
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Equations are Expressions of Arithmetical Computation, and properly have no place in Geometry, except as far as Quantities truly Geometrical (that is, Lines, Surfaces, Solids, and Proportions) may be said to be some equal to others. Multiplications, Divisions, and such sort of Computations, are newly received into Geometry, and that unwarily, and contrary to the first Design of this Science. For whosoever considers the Construction of a Problem by a right Line and a Circle, found out by the first Geometricians, will easily perceive that Geometry was invented that we might expeditiously avoid, by drawing Lines, the Tediousness of Computation. Therefore these two Sciences ought not to be confounded. The Ancients did so industriously distinguish them from one another, that they never introduced Arithmetical Terms into Geometry. And the Moderns, by confounding both, have lost the Simplicity in which all the Elegance of Geometry consists. Wherefore that is Arithmetically more simple which is determined by the more simple Equation, but that is Geometrically more simple which is determined by the more simple drawing of Lines; and in Geometry, that ought to be reckoned best which is geometrically most simple.
In 'On the Linear Construction of Equations', Universal Arithmetic (1769), Vol. 2, 470.
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Experiments may be of two kinds: experiments of simple fact, and experiments of quantity. ...[In the latter] the conditions will ... vary, not in quality, but quantity, and the effect will also vary in quantity, so that the result of quantitative induction is also to arrive at some mathematical expression involving the quantity of each condition, and expressing the quantity of the result. In other words, we wish to know what function the effect is of its conditions. We shall find that it is one thing to obtain the numerical results, and quite another thing to detect the law obeyed by those results, the latter being an operation of an inverse and tentative character.
Principles of Science: A Treatise on Logic and Scientific Method (1874, 1892), 439.
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For we may remark generally of our mathematical researches, that these auxiliary quantities, these long and difficult calculations into which we are often drawn, are almost always proofs that we have not in the beginning considered the objects themselves so thoroughly and directly as their nature requires, since all is abridged and simplified, as soon as we place ourselves in a right point of view.
In Théorie Nouvelle de la Rotation des Corps (1834). As translated by Charles Thomas Whitley in Outlines of a New Theory of Rotatory Motion (1834), 4.
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GRAVITATION, n. The tendency of all bodies to approach one another with a strength proportioned to the quantity of matter they contain—the quantity of matter they contain being ascertained by the strength of their tendency to approach one another. This is a lovely and edifying illustration of how science, having made A the proof of B, makes B the proof of A.
The Collected Works of Ambrose Bierce (1911), Vol. 7, The Devil's Dictionary,  123.
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Heat may be considered, either in respect of its quantity, or of its intensity. Thus two lbs. of water, equally heated, must contain double the quantity that one of them does, though the thermometer applied to them separately, or together, stands at precisely the same point, because it requires double the time to heat two lbs. as it does to heat one.
In Alexander Law, Notes of Black's Lectures, vol. 1, 5. Cited in Charles Coulston Gillispie, Dictionary of Scientific Biography: Volumes 1-2 (1981), 178.
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I am afraid all we can do is to accept the paradox and try to accommodate ourselves to it, as we have done to so many paradoxes lately in modern physical theories. We shall have to get accustomed to the idea that the change of the quantity R, commonly called the 'radius of the universe', and the evolutionary changes of stars and stellar systems are two different processes, going on side by side without any apparent connection between them. After all the 'universe' is an hypothesis, like the atom, and must be allowed the freedom to have properties and to do things which would be contradictory and impossible for a finite material structure.
Kosmos (1932), 133.
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I had a feeling once about Mathematics—that I saw it all. Depth beyond depth was revealed to me—the Byss and Abyss. I saw—as one might see the transit of Venus or even the Lord Mayor’s Show—a quantity passing through infinity and changing its sign from plus to minus. I saw exactly why it happened and why the tergiversation was inevitable but it was after dinner and I let it go.
In Sir Winston Churchill: A Self-Portrait (1954), 38.
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I have no doubt that many small strikes of a hammer will finally have as much effect as one very heavy blow: I say as much in quantity, although they may be different in mode, but in my opinion, everything happens in nature in a mathematical way, and there is no quantity that is not divisible into an infinity of parts; and Force, Movement, Impact etc. are types of quantities.
From the original French, “Ie ne doute point que plusieurs petits coups de Marteau ne fassent enfin autant d’effet qu’vn fort grand coup, ie dis autant en quantité, bien qu’ils puissent estre différents, in modo; mais apud me omnia fiunt Mathematicè in Natura, & il n’y a point de quantité qui ne soit divisible en une infinité de parties; Or la Force, le Mouuement, la Percussion, &c. sont des Especes de quantitez,” in letter (11 Mar 1640) to Père Marin Mersenne (AT III 36), collected in Lettres de Mr Descartes (1659), Vol. 2, 211-212. English version by Webmaster using online resources.
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I would ... change the accepted rule that the nature of a complex molecule is determined by the nature, quantity, and position of its elementary component parts, by the following statement: the chemical nature of a complex molecule is determined by the nature of its elementary component parts, their quantity and chemical structure.
'On the Chemical Structure of Substances' 1861.
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I’m one of the most durable and fervent advocates of space exploration, but my take is that we could do it robotically at far less cost and far greater quantity and quality of results.
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If a nonnegative quantity was so small that it is smaller than any given one, then it certainly could not be anything but zero. To those who ask what the infinitely small quantity in mathematics is, we answer that it is actually zero. Hence there are not so many mysteries hidden in this concept as they are usually believed to be. These supposed mysteries have rendered the calculus of the infinitely small quite suspect to many people. Those doubts that remain we shall thoroughly remove in the following pages, where we shall explain this calculus.
…...
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If E is considered to be a continuously divisible quantity, this distribution is possible in infinitely many ways. We consider, however—this is the most essential point of the whole calculation—E to be composed of a well-defined number of equal parts and use thereto the constant of nature h = 6.55 ×10-27 erg sec. This constant multiplied by the common frequency ν of the resonators gives us the energy element ε in erg, and dividing E by ε we get the number P of energy elements which must be divided over the N resonators.
[Planck’s constant, as introduced in 1900; subsequently written e = hν.]
In 'On the theory of the energy distribution law of the normal spectrum', in D. ter Haar and Stephen G. Brush, trans., Planck’s Original Papers in Quantum Physics (1972), 40.
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If experiments are performed thousands of times at all seasons and in every place without once producing the effects mentioned by your philosophers, poets, and historians, this will mean nothing and we must believe their words rather our own eyes? But what if I find for you a state of the air that has all the conditions you say are required, and still the egg is not cooked nor the lead ball destroyed? Alas! I should be wasting my efforts... for all too prudently you have secured your position by saying that 'there is needed for this effect violent motion, a great quantity of exhalations, a highly attenuated material and whatever else conduces to it.' This 'whatever else' is what beats me, and gives you a blessed harbor, a sanctuary completely secure.
'The Assayer' (1623), trans. Stillman Drake, Discoveries and Opinions of Galileo (1957), 273.
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If it is possible to have a linear unit that depends on no other quantity, it would seem natural to prefer it. Moreover, a mensural unit taken from the earth itself offers another advantage, that of being perfectly analogous to all the real measurements that in ordinary usage are also made upon the earth, such as the distance between two places or the area of some tract, for example. It is far more natural in practice to refer geographical distances to a quadrant of a great circle than to the length of a pendulum.
'Histoire'. Histoire et Memoires de l’Academie Royale des Science de Paris (1788/1791), 9-10. In Charles Coulston Gillispie, Pierre-Simon Laplace, 1749-1827: A Life in Exact Science (2nd Ed., 2000), 151.
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If the observation of the amount of heat the sun sends the earth is among the most important and difficult in astronomical physics, it may also be termed the fundamental problem of meteorology, nearly all whose phenomena would become predictable, if we knew both the original quantity and kind of this heat.
In Report of the Mount Whitney Expedition, quoted in Charles Greeley Abbot, Adventures in the World of Science (1958), 17. Also quoted and cited in David H. Devorkin, 'Charles Greeley Abbot', Biographical Memoirs (1998), 4.
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If the world may be thought of as a certain definite quantity of force and as a certain definite number of centers of force—and every other representation remains indefinite and therefore useless—it follows that, in the great dice game of existence, it must pass through calculable number of combinations. In infinite time, every possible combination would at some time or another be realized; more: it would be realized an infinite number of times. And since between every combination and its next recurrence all other possible combinations would have to take place, and each of these combination conditions of the entire sequence of combinations in the same series, a circular movement of absolutely identical series is thus demonstrated: the world as a circular movement that has already repeated itself infinitely often and plays its game in infinitum. This conception is not simply a mechanistic conception; for if it were that, it would not condition an infinite recurrence of identical cases, but a final state. Because the world has not reached this, mechanistic theory must be considered an imperfect and merely provisional hypothesis.
The Will to Power (Notes written 1883-1888), book 4, no. 1066. Trans. W. Kaufmann and R. J. Hollingdale and ed. W. Kaufmann (1968), 549.
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If we take in our hand any Volume; of Divinity or School Metaphysics, for Instance; let us ask, Does it contain any abstract Reasoning concerning Quantity or Number? No. Does it contain any experimental Reasoning concerning Matter of Fact and Existence? No. Commit it then to the Flames: For it can contain nothing but Sophistry and Illusion.
An Enquiry Concerning Human Understanding (1748), 256.
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If you free yourself from the conventional reaction to a quantity like a million years, you free yourself a bit from the boundaries of human time. And then in a way you do not live at all, but in another way you live forever.
In Basin and Range (1981), 135.
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Imagine a person with a gift of ridicule [He might say] First that a negative quantity has no logarithm; secondly that a negative quantity has no square root; thirdly that the first non-existent is to the second as the circumference of a circle is to the diameter.
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In abstract mathematical theorems, the approximation to absolute truth is perfect. … In physical science, on the contrary, we treat of the least quantities which are perceptible.
In The Principles of Science: A Treatise on Logic and Scientific Method (1913), 478.
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In all cases where work is produced by heat, a quantity of heat proportional to the work done is expended; and inversely, by the expenditure of a like quantity of work, the same amount of heat may be produced.
'On the Moving Force of Heat, and the Laws regarding the Nature of Heat itself which are deducible therefrom', Philosophical Magazine, 1851, 2, 4.
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In defining an element let us not take an external boundary, Let us say, e.g., the smallest ponderable quantity of yttrium is an assemblage of ultimate atoms almost infinitely more like each other than they are to the atoms of any other approximating element. It does not necessarily follow that the atoms shall all be absolutely alike among themselves. The atomic weight which we ascribe to yttrium, therefore, merely represents a mean value around which the actual weights of the individual atoms of the “element” range within certain limits. But if my conjecture is tenable, could we separate atom from atom, we should find them varying within narrow limits on each side of the mean.
Address to Annual General Meeting of the Chemical Society (28 Mar 1888), printed in Journal of the Chemical Society (1888), 491.
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In Euclid each proposition stands by itself; its connection with others is never indicated; the leading ideas contained in its proof are not stated; general principles do not exist. In modern methods, on the other hand, the greatest importance is attached to the leading thoughts which pervade the whole; and general principles, which bring whole groups of theorems under one aspect, are given rather than separate propositions. The whole tendency is toward generalization. A straight line is considered as given in its entirety, extending both ways to infinity, while Euclid is very careful never to admit anything but finite quantities. The treatment of the infinite is in fact another fundamental difference between the two methods. Euclid avoids it, in modern mathematics it is systematically introduced, for only thus is generality obtained.
In 'Geometry', Encyclopedia Britannica (9th edition).
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In general, the bigger a mountain the older it is. The biggest mountains were built before any others, because when they were built there was incomparably more flammable material within the Earth. Over the many thousands of years that have passed, the quantity of flammable material has doubtless decreased.
On the Strata of the Earth (1763), paragraph 119.
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In geometric and physical applications, it always turns out that a quantity is characterized not only by its tensor order, but also by symmetry.
Epigraph in Charles W. Misner, Kip S. Thorn and John Archibald Wheeler, Gravitation (1970, 1973), 47. Cited as “(1925),” with no source.
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In man, then, let us take the amount that is extruded by the individual beats, and that cannot return into the heart because of the barrier set in its way by the valves, as half an ounce, or three drachms, or at least one drachm. In half an hour the heart makes over a thousand beats; indeed, in some individuals, and on occasion, two, three, or four thousand. If you multiply the drachms per beat by the number of beats you will see that in half an hour either a thousand times three drachms or times two drachms, or five hundred ounces, or other such proportionate quantity of blood has been passed through the heart into the arteries, that is, in all cases blood in greater amount than can be found in the whole of the body. Similarly in the sheep or the dog. Let us take it that one scruple passes in a single contraction of the heart; then in half an hour a thousand scruples, or three and a half pounds of blood, do so. In a body of this size, as I have found in the sheep, there is often not more than four pounds of blood.
In the above sort of way, by calculating the amount of blood transmitted [at each heart beat] and by making a count of the beats, let us convince ourselves that the whole amount of the blood mass goes through the heart from the veins to the arteries and similarly makes the pulmonary transit.
Even if this may take more than half an hour or an hour or a day for its accomplishment, it does nevertheless show that the beat of the heart is continuously driving through that organ more blood than the ingested food can supply, or all the veins together at any time contain.
De Motu Cordis (1628), The Circulation of the Blood and Other Writings, trans. Kenneth J. Franklin (1957), Chapter 9, 62-3.
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In the physical world, one cannot increase the size or quantity of anything without changing its quality. Similar figures exist only in pure geometry.
In W.H. Auden and ‎Louis Kronenberger, The Viking Book of Aphorisms: A Personal Selection, (1966), 98.
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In the vast cosmical changes, the universal life comes and goes in unknown quantities ... sowing an animalcule here, crumbling a star there, oscillating and winding, ... entangling, from the highest to the lowest, all activities in the obscurity of a dizzying mechanism, hanging the flight of an insect upon the movement of the earth... Enormous gearing, whose first motor is the gnat, and whose last wheel is the zodiac.
Victor Hugo and Charles E. Wilbour (trans.), Les Misérables (1862), 41.
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IODINE
It was Courtois discover'd Iodine
(In the commencement of this century),
Which, with its sisters, bromine and chlorine,
Enjoys a common parentage - the sea;
Although sometimes 'tis found, with other things,
In minerals and many saline springs.

But yet the quantity is so minute
In the great ocean, that a chemist might,
With sensibilities the most acute,
Have never brought this element to light,
Had he not thought it were as well to try
Where ocean's treasures concentrated lie.

And Courtois found that several plants marine,
Sponges, et cetera, exercise the art
Of drawing from the sea its iodine
In quantities sufficient to impart
Its properties; and he devised a plan
Of bringing it before us - clever man!
Anonymous
Discursive Chemical Notes in Rhyme (1876) by the Author of the Chemical Review, a B.
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It is from this absolute indifference and tranquility of the mind, that mathematical speculations derive some of their most considerable advantages; because there is nothing to interest the imagination; because the judgment sits free and unbiased to examine the point. All proportions, every arrangement of quantity, is alike to the understanding, because the same truths result to it from all; from greater from lesser, from equality and inequality.
In On the Sublime and Beautiful, Part 3, sect. 2.
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It is not of the essence of mathematics to be conversant with the ideas of number and quantity. Whether as a general habit of mind it would be desirable to apply symbolic processes to moral argument, is another question.
An Investigation of the Laws of Thought (1854), 12.
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It is probable that all heavy matter possesses—latent and bound up with the structure of the atom—a similar quantity of energy to that possessed by radium. If it could be tapped and controlled, what an agent it would be in shaping the world's destiny! The man who puts his hand on the lever by which a parsimonious nature regulates so jealously the output of this store of energy would possess a weapon by which he could destroy the Earth if he chose.
A prescient remark on atomic energy after the discovery of radioactivity, but decades before the harnessing of nuclear fission in an atomic bomb became a reality.
Lecture to the Corps of Royal Engineers, Britain (19040. In Rodney P. Carlisle, Scientific American Inventions and Discoveries (2004), 373.
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It remains a real world if there is a background to the symbols—an unknown quantity which the mathematical symbol x stands for. We think we are not wholly cut off from this background. It is to this background that our own personality and consciousness belong, and those spiritual aspects of our nature not to be described by any symbolism… to which mathematical physics has hitherto restricted itself.
Swarthmore Lecture (1929) at Friends’ House, London, printed in Science and the Unseen World (1929), 37-38.
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It seems to me, that the only Objects of the abstract Sciences or of Demonstration is Quantity and Number, and that all Attempts to extend this more perfect Species of Knowledge beyond these Bounds are mere Sophistry and Illusion.
An Enquiry Concerning Human Understanding (1748), 252.
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It was a great step in science when men became convinced that, in order to understand the nature of things, they must begin by asking, not whether a thing is good or bad, noxious or beneficial, but of what kind it is? And how much is there of it? Quality and Quantity were then first recognised as the primary features to be observed in scientific inquiry.
'Address to the Mathematical and Physical Sections of the British Association, Liverpool, 15 Sep 1870', The Scientific Papers of James Clerk Maxwell (1890 edition, reprint 2003), Vol. 2, 217.
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It was his [Leibnitz’s] love of method and order, and the conviction that such order and harmony existed in the real world, and that our success in understanding it depended upon the degree and order which we could attain in our own thoughts, that originally was probably nothing more than a habit which by degrees grew into a formal rule. This habit was acquired by early occupation with legal and mathematical questions. We have seen how the theory of combinations and arrangements of elements had a special interest for him. We also saw how mathematical calculations served him as a type and model of clear and orderly reasoning, and how he tried to introduce method and system into logical discussions, by reducing to a small number of terms the multitude of compound notions he had to deal with. This tendency increased in strength, and even in those early years he elaborated the idea of a general arithmetic, with a universal language of symbols, or a characteristic which would be applicable to all reasoning processes, and reduce philosophical investigations to that simplicity and certainty which the use of algebraic symbols had introduced into mathematics.
A mental attitude such as this is always highly favorable for mathematical as well as for philosophical investigations. Wherever progress depends upon precision and clearness of thought, and wherever such can be gained by reducing a variety of investigations to a general method, by bringing a multitude of notions under a common term or symbol, it proves inestimable. It necessarily imports the special qualities of number—viz., their continuity, infinity and infinite divisibility—like mathematical quantities—and destroys the notion that irreconcilable contrasts exist in nature, or gaps which cannot be bridged over. Thus, in his letter to Arnaud, Leibnitz expresses it as his opinion that geometry, or the philosophy of space, forms a step to the philosophy of motion—i.e., of corporeal things—and the philosophy of motion a step to the philosophy of mind.
In Leibnitz (1884), 44-45. [The first sentence is reworded to better introduce the quotation. —Webmaster]
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It will be noticed that the fundamental theorem proved above bears some remarkable resemblances to the second law of thermodynamics. Both are properties of populations, or aggregates, true irrespective of the nature of the units which compose them; both are statistical laws; each requires the constant increase of a measurable quantity, in the one case the entropy of a physical system and in the other the fitness, measured by m, of a biological population. As in the physical world we can conceive the theoretical systems in which dissipative forces are wholly absent, and in which the entropy consequently remains constant, so we can conceive, though we need not expect to find, biological populations in which the genetic variance is absolutely zero, and in which fitness does not increase. Professor Eddington has recently remarked that “The law that entropy always increases—the second law of thermodynamics—holds, I think, the supreme position among the laws of nature.” It is not a little instructive that so similar a law should hold the supreme position among the biological sciences. While it is possible that both may ultimately be absorbed by some more general principle, for the present we should note that the laws as they stand present profound differences—-(1) The systems considered in thermodynamics are permanent; species on the contrary are liable to extinction, although biological improvement must be expected to occur up to the end of their existence. (2) Fitness, although measured by a uniform method, is qualitatively different for every different organism, whereas entropy, like temperature, is taken to have the same meaning for all physical systems. (3) Fitness may be increased or decreased by changes in the environment, without reacting quantitatively upon that environment. (4) Entropy changes are exceptional in the physical world in being irreversible, while irreversible evolutionary changes form no exception among biological phenomena. Finally, (5) entropy changes lead to a progressive disorganization of the physical world, at least from the human standpoint of the utilization of energy, while evolutionary changes are generally recognized as producing progressively higher organization in the organic world.
The Genetical Theory of Natural Selection (1930), 36.
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It would be difficult and perhaps foolhardy to analyze the chances of further progress in almost every part of mathematics one is stopped by unsurmountable difficulties, improvements in the details seem to be the only possibilities which are left… All these difficulties seem to announce that the power of our analysis is almost exhausted, even as the power of ordinary algebra with regard to transcendental geometry in the time of Leibniz and Newton, and that there is a need of combinations opening a new field to the calculation of transcendental quantities and to the solution of the equations including them.
From Rapport historique sur les progrès des sciences mathématiques depuis 1789, et sur leur état actuel (1810), 131. As translated in George Sarton, The Study of the History of Mathematics (1936), 13. In the original French: “Il seroit difficile et peut-être téméraire d’analyser les chances que l’avenir offre à l’avancement des mathématiques: dans presque toutes les parties, on est arrêté par des difficultés insurmontables; des perfectionnements de détail semblent la seule chose qui reste à faire… Toutes ces difficultés semblent annoncer que la puissance de notre analyse est à-peu-près épuisée, comme celle de l’algèbre ordinaire l’étoit par rapport à la géométrie transcendante au temps de Leibnitz et de Newton, et qu’il faut des combinaisons qui ouvrent un nouveau champ au calcul des transcendantes et à la résolution des équations qui les contiennent.” Sarton states this comes from “the report on mathematical progress prepared for the French Academy of Sciences at Napoleon’s request”.
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Logic, like whiskey, loses its beneficial effect when taken in too large quantities.
In 'Weeds and Moss', My Ireland (1937), Chap. 19, 186.
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Mathematic is either Pure or Mixed: To Pure Mathematic belong those sciences which handle Quantity entirely severed from matter and from axioms of natural philosophy. These are two, Geometry and Arithmetic; the one handling quantity continued, the other dissevered. … Mixed Mathematic has for its subject some axioms and parts of natural philosophy, and considers quantity in so far as it assists to explain, demonstrate and actuate these.
In De Augmentis, Bk. 3; Advancement of Learning, Bk. 2.
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MATHEMATICS … the general term for the various applications of mathematical thought, the traditional field of which is number and quantity. It has been usual to define mathematics as “the science of discrete and continuous magnitude.”
Opening statement in article 'Mathematics', Encyclopedia Britannica (1911, 11th ed.), Vol. 17, 878. Whitehead then indicated this was an inadequate definition, which he then discussed at length and tried to give an improved definition later in the article. See the quote beginning “Definition of Mathematics…” on the Alfred North Whitehead Quotes page on this website.
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Mathematics is that form of intelligence in which we bring the objects of the phenomenal world under the control of the conception of quantity.
Offered as a provision definition, in 'The Departments of Mathematics, and their Mutual Relations', Journal of Speculative Philosophy (Apr 1871), 5, No. 2, 164.
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My experiments proved that the radiation of uranium compounds ... is an atomic property of the element of uranium. Its intensity is proportional to the quantity of uranium contained in the compound, and depends neither on conditions of chemical combination, nor on external circumstances, such as light or temperature.
... The radiation of thorium has an intensity of the same order as that of uranium, and is, as in the case of uranium, an atomic property of the element.
It was necessary at this point to find a new term to define this new property of matter manifested by the elements of uranium and thorium. I proposed the word radioactivity which has since become generally adopted; the radioactive elements have been called radio elements.
In Pierre Curie, with the Autobiographical Notes of Marie Curie, trans. Charlotte and Vernon Kellogg (1923), 96. Also in reprint (2012) 45-46.
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My sense is that the most under-appreciated–and perhaps most under-researched–linkages between forests and food security are the roles that forest-based ecosystem services play in underpinning sustainable agricultural production. Forests regulate hydrological services including the quantity, quality, and timing of water available for irrigation. Forest-based bats and bees pollinate crops. Forests mitigate impacts of climate change and extreme weather events at the landscape scale.
In 'Forests and food security: What we know and need to know', Forest News online blog by the Center for International Forestry Research (20 Apr 2011).
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No matter how far you have wandered hitherto, or how many famous gorges and valleys you have seen, this one, the Grand Cañon of the Colorado, will seem as novel to you, as unearthly in the color and grandeur and quantity of its architecture, as if you have found it after death, on some other star.
John Muir
In 'The Wild Parks and Forest Reservations of the West', The Atlantic Monthly (1896), 81, 28.
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Notable enough, however, are the controversies over the series 1 – 1 + 1 – 1 + 1 – … whose sum was given by Leibniz as 1/2, although others disagree. … Understanding of this question is to be sought in the word “sum”; this idea, if thus conceived—namely, the sum of a series is said to be that quantity to which it is brought closer as more terms of the series are taken—has relevance only for convergent series, and we should in general give up the idea of sum for divergent series.
…...
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October 9, 1863
Always, however great the height of the balloon, when I have seen the horizon it has roughly appeared to be on the level of the car though of course the dip of the horizon is a very appreciable quantity or the same height as the eye. From this one might infer that, could the earth be seen without a cloud or anything to obscure it, and the boundary line of the plane approximately the same height as the eye, the general appearance would be that of a slight concavity; but I have never seen any part of the surface of the earth other than as a plane.
Towns and cities, when viewed from the balloon are like models in motion. I shall always remember the ascent of 9th October, 1863, when we passed over London about sunset. At the time when we were 7,000 feet high, and directly over London Bridge, the scene around was one that cannot probably be equalled in the world. We were still so low as not to have lost sight of the details of the spectacle which presented itself to our eyes; and with one glance the homes of 3,000,000 people could be seen, and so distinct was the view, that every large building was easily distinguishable. In fact, the whole of London was visible, and some parts most clearly. All round, the suburbs were also very distinct, with their lines of detached villas, imbedded as it were in a mass of shrubs; beyond, the country was like a garden, its fields, well marked, becoming smaller and smaller as the eye wandered farther and farther away.
Again looking down, there was the Thames, throughout its whole length, without the slightest mist, dotted over its winding course with innumerable ships and steamboats, like moving toys. Gravesend was visible, also the mouth of the Thames, and the coast around as far as Norfolk. The southern shore of the mouth of the Thames was not so clear, but the sea beyond was seen for many miles; when at a higher elevation, I looked for the coast of France, but was unable to see it. On looking round, the eye was arrested by the garden-like appearance of the county of Kent, till again London claimed yet more careful attention.
Smoke, thin and blue, was curling from it, and slowly moving away in beautiful curves, from all except one part, south of the Thames, where it was less blue and seemed more dense, till the cause became evident; it was mixed with mist rising from the ground, the southern limit of which was bounded by an even line, doubtless indicating the meeting of the subsoils of gravel and clay. The whole scene was surmounted by a canopy of blue, everywhere free from cloud, except near the horizon, where a band of cumulus and stratus extended all round, forming a fitting boundary to such a glorious view.
As seen from the earth, the sunset this evening was described as fine, the air being clear and the shadows well defined; but, as we rose to view it and its effects, the golden hues increased in intensity; their richness decreased as the distance from the sun increased, both right and left; but still as far as 90º from the sun, rose-coloured clouds extended. The remainder of the circle was completed, for the most part, by pure white cumulus of well-rounded and symmetrical forms.
I have seen London by night. I have crossed it during the day at the height of four miles. I have often admired the splendour of sky scenery, but never have I seen anything which surpassed this spectacle. The roar of the town heard at this elevation was a deep, rich, continuous sound the voice of labour. At four miles above London, all was hushed; no sound reached our ears.
Travels in the Air (1871), 99-100.
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Of the various anesthetics which have been introduced for surgical use, only two deserve to be considered, and in order of preference they are ether and chloroform. In general, there is no comparison between these agents. Ether is so much safer than chloroform that the latter is fast disappearing in practice. In the present rapid progress of science it can not but be a short while until chloroform will only he employed in a very limited number of cases. The estimated death-rate after ether is 1 in 20,000, in chloroform 1 in 3,000. All of the objections to ether by the advocates of chloroform narcosis—namely, its slowness of action, irritation of the respiratory tract, nausea and vomiting, inflammability, extra quantity required, etc.—fade into insignificance when brought face to face with the fact that about seven lives are sacrificed by chloroform to one by ether.
In A Text-Book on Surgery: General, Operative, and Mechanical (1887), 24.
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Ohm (a distinguished mathematician, be it noted) brought into order a host of puzzling facts connecting electromotive force and electric current in conductors, which all previous electricians had only succeeded in loosely binding together qualitatively under some rather vague statements. Even as late as 20 years ago, “quantity” and “tension” were much used by men who did not fully appreciate Ohm's law. (Is it not rather remarkable that some of Germany's best men of genius should have been, perhaps, unfairly treated? Ohm; Mayer; Reis; even von Helmholtz has mentioned the difficulty he had in getting recognised. But perhaps it is the same all the world over.)
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On the 20th of May 1747, I took twelve patients in the scurvy, on board the Salisbury at sea. Their cases were as similar as I could have them. They all in general had putrid gums, the spots and lassitude, with weakness of their knees. They lay together in one place, being a proper apartment for the sick in the fore-hold; and had one diet common to all, viz, water-gruel sweetened with sugar in the morning; fresh mutton-broth often times for dinner; at other times puddings, boiled biscuit with sugar, &c.; and for supper, barley and raisins, rice and currents, sago and wine, or the like.
Two of these were ordered each a quart of cider a-day. Two others took twenty-five gutta of elixir vitriol three times a-day, upon an empty stomach; using a gargle strongly acidulated with it for their mouths. Two others took two spoonfuls of vinegar three times a-day, upon an empty stomach; having their gruels and their other food well acidulated with it, as also the gargle for their mouth. Two of the worst patients, with the tendons in the ham rigid, (a symptom none of the rest had), were put under a course of sea-water. Of this they drank half a pint every day, and sometimes more or less as it operated, by way of gentle physics. The others had each two oranges and one lemon given them every day. These they eat with greediness, at different times, upon an empty stomach. They continued but six days under this course, having consumed the quantity that could be spared. The two remaining patients, took the bigness of a nutmeg three times a-day, of an electuary recommended by an hospital-surgeon, made of garlic, mustard-seed, rad. raphan. balsam of Peru, and gum myrrh; using for common drink, barley-water well acidulated with tamarinds; by a decoction of which, with the addition of cremor tartar, they were gently purged three or four times during the course.
The consequence was, that the most sudden and visible good effects were perceived from the use of the oranges and lemons; one of those who had taken them, being at the end of six days fit for duty. …
Next to the oranges, I thought the cider had the best effects.
A Treatise of the Scurvy (1753), 191-193. Quoted in Carleton Ellis and Annie Louise Macleod, Vital Factors of Foods: Vitamins and Nutrition (1922), 229-230.
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Opium is the only drug to' be rely'd on—all the boasted nostrums only take up time, and as the disease [is] often of short duration, or of small quantity, they have gain'd credit which they do not deserve.
Quoted in Desmond King-Hele, Erasmus Darwin: A Life of Unequalled Achievement (1999), 161.
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Physical changes take place continuously, while chemical changes take place discontinuously. Physics deals chiefly with continuous varying quantities, while chemistry deals chiefly with whole numbers.
Treatise on Thermodynamics (1897), trans. Alexander Ogg (1903), 22, footnote.
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Quantity is that which is operated with according to fixed mutually consistent laws. Both operator and operand must derive their meaning from the laws of operation. In the case of ordinary algebra these are the three laws already indicated [the commutative, associative, and distributive laws], in the algebra of quaternions the same save the law of commutation for multiplication and division, and so on. It may be questioned whether this definition is sufficient, and it may be objected that it is vague; but the reader will do well to reflect that any definition must include the linear algebras of Peirce, the algebra of logic, and others that may be easily imagined, although they have not yet been developed. This general definition of quantity enables us to see how operators may be treated as quantities, and thus to understand the rationale of the so called symbolical methods.
In 'Mathematics', Encyclopedia Britannica (9th ed.).
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Secondly, the study of mathematics would show them the necessity there is in reasoning, to separate all the distinct ideas, and to see the habitudes that all those concerned in the present inquiry have to one another, and to lay by those which relate not to the proposition in hand, and wholly to leave them out of the reckoning. This is that which, in other respects besides quantity is absolutely requisite to just reasoning, though in them it is not so easily observed and so carefully practised. In those parts of knowledge where it is thought demonstration has nothing to do, men reason as it were in a lump; and if upon a summary and confused view, or upon a partial consideration, they can raise the appearance of a probability, they usually rest content; especially if it be in a dispute where every little straw is laid hold on, and everything that can but be drawn in any way to give color to the argument is advanced with ostentation. But that mind is not in a posture to find truth that does not distinctly take all the parts asunder, and, omitting what is not at all to the point, draws a conclusion from the result of all the particulars which in any way influence it.
In Conduct of the Understanding, Sect. 7.
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Sheppey hath long been noted for producing large quantities of Sheep (whence probably its name is derived) as well as Corn; and exhibits to the Curious Naturalist a most desirable Spot, by affording many rare Plants, and more especially in the of its Northern Cliffs, so great a Quantity and Variety of Fossils, both native and extraneous are scarcely to be paralleled. These Cliffs length about six miles; Minster, Shurland and Warden are the Manors to which they appertain, the more elevated parts whereof reach about thirds of their extension, and are at the very highest of them not less than fifty yards perpendicular height above the Beach and Shore.
Quoted in Augustus A. Daly, History of the Isle of Sheppey (1975), 247.
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Since the stomach gives no obvious external sign of its workings, investigators of gastric movements have hitherto been obliged to confine their studies to pathological subjects or to animals subjected to serious operative interference. Observations made under these necessarily abnormal conditions have yielded a literature which is full of conflicting statements and uncertain results. The only sure conclusion to be drawn from this material is that when the stomach receives food, obscure peristaltic contractions are set going, which in some way churn the food to a liquid chyme and force it into the intestines. How imperfectly this describes the real workings of the stomach will appear from the following account of the actions of the organ studied by a new method. The mixing of a small quantity of subnitrate of bismuth with the food allows not only the contractions of the gastric wall, but also the movements of the gastric contents to be seen with the Röntgen rays in the uninjured animal during normal digestion.
In 'The Movements of the Stomach Studied by Means of the Röntgen Rays,' American Journal of Physiology (1898), 1, 359-360.
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Some guns were fired to give notice that the departure of the balloon was near. ... Means were used, I am told, to prevent the great balloon's rising so high as might endanger its bursting. Several bags of sand were taken on board before the cord that held it down was cut, and the whole weight being then too much to be lifted, such a quantity was discharged as would permit its rising slowly. Thus it would sooner arrive at that region where it would be in equilibrio with the surrounding air, and by discharging more sand afterwards, it might go higher if desired. Between one and two o’clock, all eyes were gratified with seeing it rise majestically from above the trees, and ascend gradually above the buildings, a most beautiful spectacle. When it was about two hundred feet high, the brave adventurers held out and waved a little white pennant, on both sides of their car, to salute the spectators, who returned loud claps of applause. The wind was very little, so that the object though moving to the northward, continued long in view; and it was a great while before the admiring people began to disperse. The persons embarked were Mr. Charles, professor of experimental philosophy, and a zealous promoter of that science; and one of the Messrs Robert, the very ingenious constructors of the machine.
While U.S. ambassador to France, writing about witnessing, from his carriage outside the garden of Tuileries, Paris, the first manned balloon ascent using hydrogen gas on the afternoon of 1 Dec 1783. A few days earlier, he had watched the first manned ascent in Montgolfier's hot-air balloon, on 21 Nov 1783.
Letter to Sir Charles Banks (1 Dec 1783). In The Writings of Benjamin Franklin: 1783-1788 (1906), Vol. 9, 119-120.
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Some recent philosophers seem to have given their moral approval to these deplorable verdicts that affirm that the intelligence of an individual is a fixed quantity, a quantity that cannot be augmented. We must protest and react against this brutal pessimism; we will try to demonstrate that it is founded on nothing.
Les idées modernes sur les enfants (1909), 141.
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Suppose we take a quantity of heat and change it into work. In doing so, we haven’t destroyed the heat, we have only transferred it to another place or perhaps changed it into another energy form.
From 'In the Game of Energy and Thermodynamics You Can’t Even Break Even', Smithsonian (Aug 1970), 1, No. 5, 6.
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That the master manufacturer, by dividing the work to be executed into different processes, each requiring different degrees of skill or of force, can purchase precisely the precise quantity of both which is necessary for each process; whereas, if the whole work were executed by one workman, that person must possess sufficient skill to perform the most difficult, and sufficient strength to execute the most laborious, of the operations into which the art is divided.
In 'On the Division of Labour', Economy of Machinery and Manufactures (1st ed., 1832), chap. 18, 127.
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The ‘Doctrine of Uniformity’ in Geology, as held by many of the most eminent of British Geologists, assumes that the earth’s surface and upper crust have been nearly as they are at present in temperature, and other physical qualities, during millions of millions of years. But the heat which we know, by observation, to be now conducted out of the earth yearly is so great, that if this action has been going on with any approach to uniformity for 20,000 million years, the amount of heat lost out of the earth would have been about as much as would heat, by 100 Cent., a quantity of ordinary surface rock of 100 times the earth’s bulk. This would be more than enough to melt a mass of surface rock equal in bulk to the whole earth. No hypothesis as to chemical action, internal fluidity, effects of pressure at great depth, or possible character of substances in the interior of the earth, possessing the smallest vestige of probability, can justify the supposition that the earth’s upper crust has remained nearly as it is, while from the whole, or from any part, of the earth, so great a quantity of heat has been lost.
In 'The “Doctrine of Uniformity” in Geology Briefly Refuted' (1866), Popular Lectures and Addresses (1891), Vol. 2, 6-7.
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The absolute extent of land in the Archipelago is not greater than that contained by Western Europe from Hungary to Spain; but, owing to the manner in which the land is broken up and divided, the variety of its productions is rather in proportion to the immense surface over which the islands are spread, than to the quantity of land which they contain.
Malay Archipelago
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The belief is growing on me that the disease is communicated by the bite of the mosquito. … She always injects a small quantity of fluid with her bite—what if the parasites get into the system in this manner.
Letter (27 May 1896) to Patrick Manson. In The Great Malaria Problem and Its Solution: From the Memoirs of Ronald Ross (1988), 72. Ross asked for Manson’s opinion; the ellipsis above, in full is: “What do you think?” As quoted in William Derek Foster, A History of Parasitology (1965), 173. (It was for this insight that Ross was awarded a Nobel Prize.)
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The business of concrete mathematics is to discover the equations which express the mathematical laws of the phenomenon under consideration; and these equations are the starting-point of the calculus, which must obtain from them certain quantities by means of others.
In Positive Philosophy, Bk. 1, chap. 2.
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The cause of rain is now, I consider, no longer an object of doubt. If two masses of air of unequal temperatures, by the ordinary currents of the winds, are intermixed, when saturated with vapour, a precipitation ensues. If the masses are under saturation, then less precipitation takes place, or none at all, according to the degree. Also, the warmer the air, the greater is the quantity of vapour precipitated in like circumstances. ... Hence the reason why rains are heavier in summer than in winter, and in warm countries than in cold.
Memoirs of the Literary and Philosophical Society of Manchester (1819), 3, 507. Quoted in George Drysdale Dempsey and Daniel Kinnear Clark, On the Drainage of Lands, Towns, & Buildings (1887), 246.
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The conception of correspondence plays a great part in modern mathematics. It is the fundamental notion in the science of order as distinguished from the science of magnitude. If the older mathematics were mostly dominated by the needs of mensuration, modern mathematics are dominated by the conception of order and arrangement. It may be that this tendency of thought or direction of reasoning goes hand in hand with the modern discovery in physics, that the changes in nature depend not only or not so much on the quantity of mass and energy as on their distribution or arrangement.
In History of European Thought in the Nineteenth Century (1903), Vol. 2, 736.
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The discovery that these soccer-ball-like molecules can be made in large quantities will have an effect on chemistry like the sowing of a bucket of flower seeds—the results will spring up everywhere from now on. I’d be surprised if we don’t see thousands of new fullerene compounds in the next few years, some of which are almost certain to have important uses.
As quoted in Malcolm W. Browne, 'Bizarre New Class of Molecules Spawns Its Own Branch of Chemistry', New York Times (25 Dec 1990), Late Edition (East Coast), L37.
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The great rapidity with which we add carbon gases to the air is as damaging as is the quantity.
From Lecture at the Royal Society, 'Climate Change on a Living Earth' (29 Oct 2007). As quoted on jameslovelock.org website.
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The intensity and quantity of polemical literature on scientific problems frequently varies inversely as the number of direct observations on which the discussions are based: the number and variety of theories concerning a subject thus often form a coefficient of our ignorance. Beyond the superficial observations, direct and indirect, made by geologists, not extending below about one two-hundredth of the Earth's radius, we have to trust to the deductions of mathematicians for our ideas regarding the interior of the Earth; and they have provided us successively with every permutation and combination possible of the three physical states of matter—solid, liquid, and gaseous.
'Address delivered by the President of Section [Geology] at Sydney (Friday, Aug 21), Report of the Eighty-Fourth Meeting of the British Association for the Advancement of Science: Australia 1914, 1915, 345.
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The mind comprehends a thing the more correctly the closer the thing approaches toward pure quantity as its origin.
Letter to Mästlin (19 Apr 1597). In Gerald James Holton, Thematic Origins of Scientific Thought: Kepler to Einstein (1985), 74.
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The more I study the things of the mind the more mathematical I find them. In them as in mathematics it is a question of quantities; they must be treated with precision. I have never had more satisfaction than in proving this in the realms of art, politics and history.
Notes made after the completion of the third chapter of Vol. 3 of La Rivolution, 22 April 1883. In E. Sparvel-Bayly (trans.), Life and Letters of H. Taine (1902-1908), Vol. 3, 239.
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The most part of leaves pour out the greatest quantity of this dephlogisticated air [oxygen] from their under surface, principally those of lofty trees.
In Tobias George Smollett (ed.), 'Experiments Upon Vegetables', The Critical Review, Or, Annals of Literature (1779), 48, 335.
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The new mathematics is a sort of supplement to language, affording a means of thought about form and quantity and a means of expression, more exact, compact, and ready than ordinary language. The great body of physical science, a great deal of the essential facts of financial science, and endless social and political problems are only accessible and only thinkable to those who have had a sound training in mathematical analysis, and the time may not be very remote when it will be understood that for complete initiation as an efficient citizen of the great complex world-wide States that are now developing, it is as necessary to be able to compute, to think in averages and maxima and minima, as it is now to be able to read and write.
Mankind in the Making (1903), 204. This is seen in a shorter form, somewhat misquoted in a paraphrase as: “Statistical thinking will one day be as necessary for efficient citizenship as the ability to read and write.” However, note that in fact, Wells refers only to “mathematical analysis” such as “averages and maxima and minima” — and did not specify (more complex) “statistics” at all! For citation of the paraphrase, see Samuel Wilks Quotations on this site.
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The observer is not he who merely sees the thing which is before his eyes, but he who sees what parts the thing is composed of. To do this well is a rare talent. One person, from inattention, or attending only in the wrong place, overlooks half of what he sees; another sets down much more than he sees, confounding it with what he imagines, or with what he infers; another takes note of the kind of all the circumstances, but being inexpert in estimating their degree, leaves the quantity of each vague and uncertain; another sees indeed the whole, but makes such an awkward division of it into parts, throwing into one mass things which require to be separated, and separating others which might more conveniently be considered as one, that the result is much the same, sometimes even worse than if no analysis had been attempted at all.
In A System of Logic Ratiocinative and Inductive (1858), 216.
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The opinion I formed from attentive observation of the facts and phenomena, is as follows. When ice, for example, or any other solid substance, is changing into a fluid by heat, I am of opinion that it receives a much greater quantity of heat than that what is perceptible in it immediately after by the thermometer. A great quantity of heat enters into it, on this occasion, without making it apparently warmer, when tried by that instrument. This heat, however, must be thrown into it, in order to give it the form of a fluid; and I affirm, that this great addition of heat is the principal, and most immediate cause of the fluidity induced. And, on the other hand, when we deprive such a body of its fluidity again, by a diminution of its heat, a very great quantity of heat comes out of it, while it is assuming a solid form, the loss of which heat is not to be perceived by the common manner of using the thermometer. The apparent heat of the body, as measured by that instrument, is not diminished, or not in proportion to the loss of heat which the body actually gives out on this occasion; and it appears from a number of facts, that the state of solidity cannot be induced without the abstraction of this great quantity of heat. And this confirms the opinion, that this quantity of heat, absorbed, and, as it were, concealed in the composition of fluids, is the most necessary and immediate cause of their fluidity.
Lectures on the Elements of Chemistry, delivered in the University of Edinburgh (1803), Vol. I, 116-7.
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The partitions of knowledge are not like several lines that meet in one angle, and so touch not in a point; but are like branches of a tree, that meet in a stem, which hath a dimension and quantity of entireness and continuance, before it come to discontinue and break itself into arms and boughs.
Francis Bacon, Basil Montagu (Ed.), The Works of Francis Bacon (1852), Vol. 1, 193.
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The physiological combustion theory takes as its starting point the fundamental principle that the amount of heat that arises from the combustion of a given substance is an invariable quantity–i.e., one independent of the circumstances accompanying the combustion–from which it is more specifically concluded that the chemical effect of the combustible materials undergoes no quantitative change even as a result of the vital process, or that the living organism, with all its mysteries and marvels, is not capable of generating heat out of nothing.
Bemerkungen über das mechanische Aequivalent der Wärme [Remarks on the Mechanical Equivalent of Heat] (1851), 17-9. Trans. Kenneth L. Caneva, Robert Mayer and the Conservation of Energy (1993), 240.
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The relationships of free and latent heat set forth in the language of the materialistic theory remain the same if in place of the quantity of matter we put the constant quantity of motion in accordance with the laws of mechanics. The only difference enters where it concerns the generations of heat through other motive forces and where it concerns the equivalent of heat that can be produced by a particular quantity of a mechanical or electrical force.
'Wärme, physiologisch', Handwörterbuch der medicinischen Wissenschaften (1845). In Timothy Lenoir, The Strategy of Life (1982), 203.
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The results of systematic symbolical reasoning must always express general truths, by their nature; and do not, for their justification, require each of the steps of the process to represent some definite operation upon quantity. The absolute universality of the interpretation of symbols is the fundamental principle of their use.
In 'The Foundations of Higher Mathematics', The Philosophy of the Inductive Sciences (1847), Part I, Bk. 2, 149.
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The role of inhibition in the working of the central nervous system has proved to be more and more extensive and more and more fundamental as experiment has advanced in examining it. Reflex inhibition can no longer be regarded merely as a factor specially developed for dealing with the antagonism of opponent muscles acting at various hinge-joints. Its role as a coordinative factor comprises that, and goes beyond that. In the working of the central nervous machinery inhibition seems as ubiquitous and as frequent as is excitation itself. The whole quantitative grading of the operations of the spinal cord and brain appears to rest upon mutual interaction between the two central processes 'excitation' and 'inhibition', the one no less important than the other. For example, no operation can be more important as a basis of coordination for a motor act than adjustment of the quantity of contraction, e.g. of the number of motor units employed and the intensity of their individual tetanic activity. This now appears as the outcome of nice co-adjustment of excitation and inhibition upon each of all the individual units which cooperate in the act.
Inhibition as a Coordinative Factor', Nobel Lecture (12 Dec 1932). Nobel Lectures: Physiology or Medicine 1922-1941 (1965), 288.
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The rudest numerical scales, such as that by which the mineralogists distinguish different degrees of hardness, are found useful. The mere counting of pistils and stamens sufficed to bring botany out of total chaos into some kind of form. It is not, however, so much from counting as from measuring, not so much from the conception of number as from that of continuous quantity, that the advantage of mathematical treatment comes. Number, after all, only serves to pin us down to a precision in our thoughts which, however beneficial, can seldom lead to lofty conceptions, and frequently descend to pettiness.
On the Doctrine of Chances, with Later Reflections (1878), 61-2.
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The saying that a little knowledge is a dangerous thing is, to my mind, a very dangerous adage. If knowledge is real and genuine, I do not believe that it is other than a very valuable posession, however infinitesimal its quantity may be. Indeed, if a little knowledge is dangerous, where is a man who has so much as to be out of danger?
'Instruction in Physiology', in Science and Culture and Other Essays (1882), 91.
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The tendency on the part of educators has ever been to make old bottles accommodate new wine quite regardless of either the size of the containers or of the quantity of the vintage.
Co-author with Louis Jay Heath, in A New Basis for Social Progress (1917), 149.
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The total disorder in the universe, as measured by the quantity that physicists call entropy, increases steadily steadily as we go from past to future. On the other hand, the total order in the universe, as measured by the complexity and permanence of organized structures, also increases steadily as we go from past to future.
From Page-Barbour lecture, University of Virginia (Mar 2004). Collected in 'A Friendly Universe', A Many-Colored Glass: Reflections on the Place of Life in the Universe (2007), 62.
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The total quantity of all the forces capable of work in the whole universe remains eternal and unchanged throughout all their changes. All change in nature amounts to this, that force can change its form and locality, without its quantity being changed. The universe possesses, once for all, a store of force which is not altered by any change of phenomena, can neither be increased nor diminished, and which maintains any change which takes place on it.
The Conservation of Energy, from a Lecture, 1863. Trans. Edmund Blair Bolles (ed.), Galileo's Commandment: An Anthology of Science Writing (2000), 407.
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The University of Cambridge, in accordance with that law of its evolution, by which, while maintaining the strictest continuity between the successive phases of its history, it adapts itself with more or less promptness to the requirements of the times, has lately instituted a course of Experimental Physics.
'Introductory Lecture on Experimental Physics', (1871). In W. D. Niven (ed.), The Scientific Papers of James Clerk Maxwell (1890), Vol. 2, 241.Course;Experiment;Cambridge;History;Promptness;Adapt;Requirement
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The whole theory of the motive power of heat is founded on the two following propositions, due respectively to Joule, and to Carnot and Clausius.
PROP. I. Joule).—When equal quantities of mechanical effect are produced by any means whatever from purely thermal sources, or lost in purely thermal effects, equal quantities of heat are put out of existence or are generated.
PROP. II. (Carnot and Clausius).—If an engine be such that, when it is worked backwards, the physical and mechanical agencies in every part of its motions are all reversed, it produces as much mechanical effect as can be produced by any thermo-dynamic engine, with the same temperatures of source and refrigerator, from a given quantity of heat.
In 'On the Dynamical Theory of Heat, with Numerical Results Deduced from Mr Joule's Equivalent of a Thermal Unit, and M. Regnault's Observations on Steam' (1851). In Mathematical and Physical Papers (1882), Vol. 1, 178.
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The wound is granulating well, the matter formed is diminishing in quantity and is laudable. But the wound is still deep and must be dressed from the bottom to ensure sound healing. … In view of the fact that sinister stories continue to be manufactured and to be printed, it may again be stated, as emphatically as possible, that during the operation no trace of malignant disease was observed, … His Majesty will leave Buckingham Palace for change of air shortly, and the date of the Coronation will be announced almost immediately.
Anonymous
In 'The King’s Progress Towards Recovery', British Medical Journal (1902), 144. The appendectomy caused the coronation of King Edward VII to be postponed.
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There is deposited in them [plants] an enormous quantity of potential energy [Spannkräfte], whose equivalent is provided to us as heat in the burning of plant substances. So far as we know at present, the only living energy [lebendige Kraft] absorbed during plant growth are the chemical rays of sunlight… Animals take up oxygen and complex oxidizable compounds made by plants, release largely as combustion products carbonic acid and water, partly as simpler reduced compounds, thus using a certain amount of chemical potential energy to produce heat and mechanical forces. Since the latter represent a relatively small amount of work in relation to the quantity of heat, the question of the conservation of energy reduces itself roughly to whether the combustion and transformation of the nutritional components yields the same amount of heat released by animals.
Wissenschaftliche Abhandlungen (1847), 66. Trans. Joseph S. Fruton, Proteins, Enzymes, Genes: The Interplay of Chemistry and Biology (1999), 247.
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There is more evidence to prove that saltiness [of the sea] is due to the admixture of some substance ... It is this stuff which makes salt water heavy (it weighs more than fresh water) and thick. The difference in consistency is such that ships with the same cargo very nearly sink in a river when they are quite fit to navigate in the sea. This circumstance has before now caused loss to shippers freighting their ships in a river. That the thicker consistency is due to an admixture of something is proved by the fact that if you make strong brine by the admixture of salt, eggs, even when they are full, float in it. It almost becomes like mud; such a quantity of earthy matter is there in the sea.
[Aristotle recognised the different density of fresh (river) or salty (sea) water. He describes an experiment using an egg (which sinks in fresh water) that floats in a strong brine solution.]
Aristotle
Meteorology (350 B.C.), Book II, translated by E. W. Webster. Internet Classics Archive, (classics.mit.edu).
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There is no quantity that is not divisible into an infinity of parts.
From the original French, “Il n’y a point de quantité qui ne soit divisible en une infinité de parties,” in letter (11 Mar 1640) to Père Marin Mersenne (AT III 36), collected in Lettres de Mr Descartes (1659), Vol. 2, 211-212. English version by Webmaster using online resources. See context in longer quote that begins, “I have no doubt….” on the René Descartes Quotes page of this website.
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This Academy [at Lagado] is not an entire single Building, but a Continuation of several Houses on both Sides of a Street; which growing waste, was purchased and applied to that Use.
I was received very kindly by the Warden, and went for many Days to the Academy. Every Room hath in it ' one or more Projectors; and I believe I could not be in fewer than five Hundred Rooms.
The first Man I saw was of a meagre Aspect, with sooty Hands and Face, his Hair and Beard long, ragged and singed in several Places. His Clothes, Shirt, and Skin were all of the same Colour. He had been Eight Years upon a Project for extracting Sun-Beams out of Cucumbers, which were to be put into Vials hermetically sealed, and let out to warm the Air in raw inclement Summers. He told me, he did not doubt in Eight Years more, that he should be able to supply the Governor's Gardens with Sunshine at a reasonable Rate; but he complained that his Stock was low, and interested me to give him something as an Encouragement to Ingenuity, especially since this had been a very dear Season for Cucumbers. I made him a small Present, for my Lord had furnished me with Money on purpose, because he knew their Practice of begging from all who go to see them.
I saw another at work to calcine Ice into Gunpowder; who likewise shewed me a Treatise he had written concerning the Malleability of Fire, which he intended to publish.
There was a most ingenious Architect who had contrived a new Method for building Houses, by beginning at the Roof, and working downwards to the Foundation; which he justified to me by the life Practice of those two prudent Insects the Bee and the Spider.
In another Apartment I was highly pleased with a Projector, who had found a device of plowing the Ground with Hogs, to save the Charges of Plows, Cattle, and Labour. The Method is this: In an Acre of Ground you bury at six Inches Distance, and eight deep, a quantity of Acorns, Dates, Chestnuts, and other Masts or Vegetables whereof these Animals are fondest; then you drive six Hundred or more of them into the Field, where in a few Days they will root up the whole Ground in search of their Food, and make it fit for sowing, at the same time manuring it with their Dung. It is true, upon Experiment they found the Charge and Trouble very great, and they had little or no Crop. However, it is not doubted that this Invention may be capable of great Improvement.
I had hitherto seen only one Side of the Academy, the other being appropriated to the Advancers of speculative Learning.
Some were condensing Air into a dry tangible Substance, by extracting the Nitre, and letting the acqueous or fluid Particles percolate: Others softening Marble for Pillows and Pin-cushions. Another was, by a certain Composition of Gums, Minerals, and Vegetables outwardly applied, to prevent the Growth of Wool upon two young lambs; and he hoped in a reasonable Time to propagate the Breed of naked Sheep all over the Kingdom.
Gulliver's Travels (1726, Penguin ed. 1967), Part III, Chap. 5, 223.
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This is one of the greatest advantages of modern geometry over the ancient, to be able, through the consideration of positive and negative quantities, to include in a single enunciation the several cases which the same theorem may present by a change in the relative position of the different parts of a figure. Thus in our day the nine principal problems and the numerous particular cases, which form the object of eighty-three theorems in the two books De sectione determinata of Appolonius constitute only one problem which is resolved by a single equation.
In Histoire de la Géométrie, chap. 1, sect. 35.
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Through and through the world is infected with quantity: To talk sense is to talk quantities. It is not use saying the nation is large—How large? It is no use saying the radium is scarce—How scarce? You cannot evade quantity. You may fly to poetry and music, and quantity and number will face you in your rhythms and your octaves.
In 'The Aims of Education', The Aims of Education: & Other Essays (1917), 11.
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Thus far I have explained the phenomena of the heavens and of our sea by the force of gravity, but I have not yet assigned a cause to gravity. Indeed, this force arises from some cause that penetrates as far as the centers of the sun and planets without any diminution of its power to act, and that acts not in proportion to the quantity of the surfaces of the particles on which it acts (as mechanical causes are wont to do) but in proportion to the quantity of solid matter, and whose action is extended everywhere to immense distances, always decreasing as the squares of the distances.
The Principia: Mathematical Principles of Natural Philosophy (1687), 3rd edition (1726), trans. I. Bernard Cohen and Anne Whitman (1999), General Scholium, 943.
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Thus the system of the world only oscillates around a mean state from which it never departs except by a very small quantity. By virtue of its constitution and the law of gravity, it enjoys a stability that can be destroyed only by foreign causes, and we are certain that their action is undetectable from the time of the most ancient observations until our own day. This stability in the system of the world, which assures its duration, is one of the most notable among all phenomena, in that it exhibits in the heavens the same intention to maintain order in the universe that nature has so admirably observed on earth for the sake of preserving individuals and perpetuating species.
'Sur l'Équation Séculaire de la Lune' (1786, published 1788). In Oeuvres complètes de Laplace, 14 Vols. (1843-1912), Vol. 11, 248-9, trans. Charles Coulston Gillispie, Pierre-Simon Laplace 1749-1827: A Life in Exact Science (1997), 145.
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Time is that which is measured by a clock. This is a sound way of looking at things. A quantity like time, or any other physical measurement, does not exist in a completely abstract way. We find no sense in talking about something unless we specify how we measure it. It is the definition by the method of measuring a quantity that is the one sure way of avoiding talking nonsense about this kind of thing.
From Relativity and Common Sense: A New Approach to Einstein (1980), 65.
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To every bushel of the powdered cement add one bushel of sand, mix them together and pass them through a sieve, then add a sufficient quantity of water to make it (by well mixing and working) about the consistency of a soft putty. It is then fit to use but should not be kept more than six or eight hours and should be thoroughly worked just before it is used.
Directions for Using White's Patent Hydraulic Cement.
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To inquisitive minds like yours and mine the reflection that the quantity of human knowledge bears no proportion to the quantity of human ignorance must be in one view rather pleasing, viz., that though we are to live forever we may be continually amused and delighted with learning something new.
In letter to Dr. Ingenhouz. Quoted in Theodore Diller, Franklin's Contribution to Medicine (1912), 65. The source gives no specific cite for the letter, and Webmaster has found the quote in no other book checked, so authenticity is in question.
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To produce any given motion, to spin a certain weight of cotton, or weave any quantity of linen, there is required steam; to produce the steam, fuel; and thus the price of fuel regulates effectively the cost of mechanical power. Abundance and cheapness of fuel are hence main ingredients in industrial success. It is for this reason that in England the active manufacturing districts mark, almost with geological accuracy, the limits of the coal fields.
In The Industrial Resources of Ireland (1844), 2.
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To the north [of Armenia] lies Zorzania [Georgia], near the confines of which there is a fountain of oil which discharges so great a quantity as to furnish loading for many camels. The use made of it is not for the purpose of food, but as an unguent for the cure of cutaneous distempers in men and cattle, as well as other complaints, and it is also good for burning. In the surrounding country no other [oil] is used in their lamps, and people come from distant parts to procure it.
[An early Western report of petroleum seepage. He visited the city of Baku, Azerbaijan in 1264.]
In The Travels of Marco Polo (c.1300, trans. reprint 2007), 21-22. Eastern records of petroleum use date back many centuries earlier.
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Typical of the fundamental scientific problems whose solution should lead to important industrial consequences are, for example, the release of atomic energy, which experiment has shown to exist in quantities millions of times greater than is liberated by combustion.
An early speculation on using the amount of energy that could be released from uranium atoms. In a letter to Henry Ford (18 May 1931). He recorded earlier thoughts on the subject in his Research Notebook, entry for 23 Jul 1930, in Arthur H. Compton Notebooks, Washington University, St. Louis, and AIP. Cited by Stanley Coben, in 'The Scientific Establishment and the Transmission of Quantum Mechanics to the United States, 1919-32', The American Historical Review (Apr 1971), 76, No. 2, 466.
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Upon viewing the milt or semen Masculinum of a living Codfish with a Microscope, such Numbers of Animalcules with long Tails were found therein, that at least ten thousand of them were supposed to exist in the quantity of a Grain of Sand.
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We find no sense in talking about something unless we specify how we measure it; a definition by the method of measuring a quantity is the one sure way of avoiding talking nonsense...
in Relativity and Common Sense (1964)
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We may lay it down as an incontestible axiom, that, in all the operations of art and nature, nothing is created; an equal quantity of matter exists both before and after the experiment; the quality and quantity of the elements remain precisely the same; and nothing takes place beyond changes and modifications in the combination of these elements. Upon this principle the whole art of performing chemical experiments depends: We must always suppose an exact equality between the elements of the body examined and those of the products of its analysis.
Elements of Chemistry trans. Robert. Kerr, (1790, 5th Ed. 1802), Vol. 1, 226.
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We may see how unexpectedly recondite parts of pure mathematics may bear upon physical science, by calling to mind the circumstance that Fresnel obtained one of the most curious confirmations of the theory (the laws of Circular Polarization by reflection) through an interpretation of an algebraical expression, which, according to the original conventional meaning of the symbols, involved an impossible quantity.
In History of Scientific Ideas, Bk. 2, chap. 14, sect. 8.
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When air has been freshly and strongly tainted with putrefaction, so as to smell through the water, sprigs of mint have presently died, upon being put into it, their leaves turning black; but if they do not die presently, they thrive in a most surprizing manner. In no other circumstances have I ever seen vegetation so vigorous as in this kind of air, which is immediately fatal to animal life. Though these plants have been crouded in jars filled with this air, every leaf has been full of life; fresh shoots have branched out in various , and have grown much faster than other similiar plants, growing in the same exposure in common air.
This observation led me to conclude that plants, instead of affecting the air in the same manner with animal respiration, reverse the effects of breathing, and tend to keep the atmosphere sweet and wholesome, when it is become noxious, in consequence on animals living and breathing, or dying and putrefying in it.
In order to ascertain this, I took a quantity of air, made thoroughly noxious, by mice breathing and dying in it, and divided it into two parts; one of which I put into a phial immersed in water; and to the other (which was contained in a glass jar, standing in water) I put a sprig of mint. This was about the beginning of August 1771, and after eight or nine days, I found that a mouse lived perfectly well in that part of the air, in which the sprig of mint had grown, but died the moment it was put into the other part of the same original quantity of air; and which I had kept in the very same exposure, but without any plant growing in it.
'Observations on Different Kinds of Air', Philosophical Transactions (1772), 62, 193-4.
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When scientists discovered that liquid water, which brought forth life on Earth, exists nowhere else in great quantities in the solar system, the most significant lesson they taught was not that water, or the life that depends on it, is necessarily the result of some chemical accident in space; their most important revelation was that water is rare in infinity, that we should prize it, preserve it, conserve it.
In Jacques Cousteau and Susan Schiefelbein, The Human, the Orchid, and the Octopus: Exploring and Conserving Our Natural World (2007), 201-202.
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When the simplest compounds of this element are considered (marsh gas, chloride of carbon, chloroform, carbonic acid, phosgene, sulphide of carbon, hydrocyanic acid, etc.) it is seen that the quantity of carbon which chemists have recognised as the smallest possible, that is, as an atom, always unites with 4 atoms of a monatomic or with two atoms of a diatomic element; that in general, the sum of the chemical units of the elements united with one atom of carbon is 4. This leads us to the view that carbon is tetratomic or tetrabasic. In the cases of substances which contain several atoms of carbon, it must be assumed that at least some of the atoms are in some way held in the compound by the affinity of carbon, and that the carbon atoms attach themselves to one another, whereby a part of the affinity of the one is naturally engaged with an equal part of the affinity of the other. The simplest and therefore the most probable case of such an association of carbon atoms is that in which one affinity unit of one is bound by one of the other. Of the 2 x 4 affinity units of the two carbon atoms, two are used up in holding the atoms together, and six remain over, which can be bound by atom)' of other elements.
'Ueber die Konstitution und die Metamorphosen der chemischen Verbindungen', Annalen (1858) 5, 106. Trans. in J. R. Partington, A History of Chemistry (1972), Vol. 4, 536.
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When there are two independent causes of variability capable of producing in an otherwise uniform population distributions with standard deviations s1 and s2, it is found that the distribution, when both causes act together, has a standard deviation vs12 + s22. It is therefore desirable in analysing the causes of variability to deal with the square of the standard deviation as the measure of variability. We shall term this quantity the Variance of the normal population to which it refers, and we may now ascribe to the constituent causes fractions or percentages of the total variance which they together produce.
'The Correlation between Relatives on the Supposition of Mendelian Inheritance,' Transactions of the Royal Society of Edinburgh, 1918, 52, 399.
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Where the flow carries a large quantity of water, the speed of the flow is greater and vice versa.
As quoted in G.A. Tokaty, A History and Philosophy of Fluid Mechanics (1994), 39. This is a precursor of the continuity equation.
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Whereas, to borrow an illustration from mathematics, life was formerly an equation of, say, 100 unknown quantities, it is now one of 99 only, inasmuch as memory and heredity have been shown to be one and the same thing.
Samuel Butler, Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1917), 57.
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Working on the final formulation of technological patents was a veritable blessing for me. It enforced many-sided thinking and also provided important stimuli to physical thought. Academia places a young person under a kind of compulsion to produce impressive quantities of scientific publications–a temptation to superficiality.
…...
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Carl Sagan Thumbnail In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. (1987) -- Carl Sagan
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- 100 -
Sophie Germain
Gertrude Elion
Ernest Rutherford
James Chadwick
Marcel Proust
William Harvey
Johann Goethe
John Keynes
Carl Gauss
Paul Feyerabend
- 90 -
Antoine Lavoisier
Lise Meitner
Charles Babbage
Ibn Khaldun
Euclid
Ralph Emerson
Robert Bunsen
Frederick Banting
Andre Ampere
Winston Churchill
- 80 -
John Locke
Bronislaw Malinowski
Bible
Thomas Huxley
Alessandro Volta
Erwin Schrodinger
Wilhelm Roentgen
Louis Pasteur
Bertrand Russell
Jean Lamarck
- 70 -
Samuel Morse
John Wheeler
Nicolaus Copernicus
Robert Fulton
Pierre Laplace
Humphry Davy
Thomas Edison
Lord Kelvin
Theodore Roosevelt
Carolus Linnaeus
- 60 -
Francis Galton
Linus Pauling
Immanuel Kant
Martin Fischer
Robert Boyle
Karl Popper
Paul Dirac
Avicenna
James Watson
William Shakespeare
- 50 -
Stephen Hawking
Niels Bohr
Nikola Tesla
Rachel Carson
Max Planck
Henry Adams
Richard Dawkins
Werner Heisenberg
Alfred Wegener
John Dalton
- 40 -
Pierre Fermat
Edward Wilson
Johannes Kepler
Gustave Eiffel
Giordano Bruno
JJ Thomson
Thomas Kuhn
Leonardo DaVinci
Archimedes
David Hume
- 30 -
Andreas Vesalius
Rudolf Virchow
Richard Feynman
James Hutton
Alexander Fleming
Emile Durkheim
Benjamin Franklin
Robert Oppenheimer
Robert Hooke
Charles Kettering
- 20 -
Carl Sagan
James Maxwell
Marie Curie
Rene Descartes
Francis Crick
Hippocrates
Michael Faraday
Srinivasa Ramanujan
Francis Bacon
Galileo Galilei
- 10 -
Aristotle
John Watson
Rosalind Franklin
Michio Kaku
Isaac Asimov
Charles Darwin
Sigmund Freud
Albert Einstein
Florence Nightingale
Isaac Newton


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