[W]e pity our fathers for dying before steam and galvanism, sulphuric ether and ocean telegraphs, photograph and spectrograph arrived, as cheated out of their human estate.

Copernicus, who rightly did condemn
This eldest systeme, form’d a wiser scheme;
In which he leaves the Sun at Rest, and rolls
The Orb Terrestial on its proper Poles;
Which makes the Night and Day by this Career,
And by its slow and crooked Course the Year.
The famous Dane, who oft the Modern guides,
To Earth and Sun their Provinces divides:
The Earth’s Rotation makes the Night and Day,
The Sun revolving through th’ Eccliptic Way
Effects the various seasons of the Year,
Which in their Turn for happy Ends appear.
This Scheme or that, which pleases best, embrace,
Still we the Fountain of their Motion trace.
Kepler asserts these Wonders may be done
By the Magnetic Vertue of the Sun,
Which he, to gain his End, thinks fit to place
Full in the Center of that mighty Space,
Which does the Spheres, where Planets roll, include,
And leaves him with Attractive Force endu’d.
The Sun, thus seated, by Mechanic Laws,
The Earth, and every distant Planet draws;
By which Attraction all the Planets found
Within his reach, are turn'd in Ether round.

A plain, reasonable working man supposes, in the old way which is also the common-sense way, that if there are people who spend their lives in study, whom he feeds and keeps while they think for him—then no doubt these men are engaged in studying things men need to know; and he expects of science that it will solve for him the questions on which his welfare, and that of all men, depends. He expects science to tell him how he ought to live: how to treat his family, his neighbours and the men of other tribes, how to restrain his passions, what to believe in and what not to believe in, and much else. And what does our science say to him on these matters?
It triumphantly tells him: how many million miles it is from the earth to the sun; at what rate light travels through space; how many million vibrations of ether per second are caused by light, and how many vibrations of air by sound; it tells of the chemical components of the Milky Way, of a new element—helium—of micro-organisms and their excrements, of the points on the hand at which electricity collects, of X rays, and similar things.
“But I don't want any of those things,” says a plain and reasonable man—“I want to know how to live.”

An animal might be frozen to death in the midst of summer by repeatedly sprinkling ether upon him, for its evaporation would shortly carry off the whole of his vital heat.

Aristotle’s opinion … that comets were nothing else than sublunary vapors or airy meteors … prevailed so far amongst the Greeks, that this sublimest part of astronomy lay altogether neglected; since none could think it worthwhile to observe, and to give an account of the wandering and uncertain paths of vapours floating in the Ether.

For if those who hold that there must be a physical basis for everything hold that these mystical views are nonsense, we may ask—What then is the physical basis of nonsense? ... In a world of ether and electrons we might perhaps encounter nonsense; we could not encounter damned nonsense.

From this time everything was copulated. Acetic, formic, butyric, margaric, &c., acids, alkaloids, ethers, amides, anilides, all became copulated bodies. So that to make acetanilide, for example, they no longer employed acetic acid and aniline, but they re-copulated a copulated oxalic acid with a copulated ammonia. I am inventing nothing—altering nothing. Is it my fault if, when writing history, I appear to be composing a romance?

Here the most sublime scene ever witnessed in the operating room was presented when the patient placed himself voluntarily upon the table, which was to become the altar of future fame. … The heroic bravery of the man who voluntarily placed himself upon the table, a subject for the surgeon’s knife, should be recorded and his name enrolled upon parchment, which should be hung upon the walls of the surgical amphitheatre in which the operation was performed. His name was Gilbert Abbott.
Description of the first public demonstration of ether at the Massachussetts General Hospital (16 Oct 1846).

I must reject fluids and ethers of all kinds, magnetical, electrical, and universal, to whatever quintessential thinness they may be treble distilled, and (as it were) super-substantiated.

I will not now discuss the Controversie betwixt some of the Modern Atomists, and the Cartesians; the former of whom think, that betwixt the Earth and the Stars, and betwixt these themselves there are vast Tracts of Space that are empty, save where the beams of Light do pass through them; and the later of whom tell us, that the Intervals betwixt the Stars and Planets (among which the Earth may perhaps be reckon'd) are perfectly fill'd, but by a Matter far subtiler than our Air, which some call Celestial, and others Æther. I shall not, I say, engage in this controversie, but thus much seems evident, That If there be such a Celestial Matter, it must ' make up far the Greatest part of the Universe known to us. For the Interstellar part of the world (If I may so stile it) bears so very great a proportion to the Globes, and their Atmospheres too, (If other Stars have any as well as the Earth,) that It Is almost incomparably Greater in respect of them, than all our Atmosphere is in respect of the Clouds, not to make the comparison between the Sea and the Fishes that swim in it.

If the 'Principle of Relativity' in an extreme sense establishes itself, it seems as if even Time would become discontinuous and be supplied in atoms, as money is doled out in pence or centimes instead of continuously;—in which case our customary existence will turn out to be no more really continuous than the events on a kinematograph screen;—while that great agent of continuity, the Ether of Space, will be relegated to the museum of historical curiosities.

In your letter you apply the word imponderable to a molecule. Don’t do that again. It may also be worth knowing that the aether cannot be molecular. If it were, it would be a gas, and a pint of it would have the same properties as regards heat, etc., as a pint of air, except that it would not be so heavy.

It has the property of detonating very violently in certain circumstances. On one occasion a small amount of ether solution of pyroglycerin condensed in a glass bowl. ... When the bowl was heated over a spirit lamp, an extremely violent explosion occurred, which shattered it into small fragments. On another occasion a drop was heated in a test-tube, and exploded with such violence that the glass splinters cut deep into my face and hands, and hurt other people who were standing some distance off in the room.
[Describing early experiments on his discovery of nitroglycerin.]

It is probable that the scheme of physics will be enlarged so as to embrace the behaviour of living organisms under the influence of life and mind. Biology and psychology are not alien sciences; their operations are not solely mechanical, nor can they be formulated by physics as it is today; but they belong to a physical universe, and their mode of action ought to be capable of being formulated in terms of an enlarged physics in the future, in which the ether will take a predominant place. On the other hand it may be thought that those entities cannot be brought to book so easily, and that they will always elude our ken. If so, there will be a dualism in the universe, which posterity will find staggering, but that will not alter the facts.

Lord Kelvin was so satisfied with this triumph of science that he declared himself to be as certain of the existence of the ether as a man can be about anything.... “When you can measure what you are speaking about, and express it in numbers, you know something about it....” Thus did Lord Kelvin lay down the law. And though quite wrong, this time he has the support of official modern Science. It is NOT true that when you can measure what you are speaking about, you know something about it. The fact that you can measure something doesn't even prove that that something exists.... Take the ether, for example: didn't they measure the ratio of its elasticity to its density?

MAGNITUDE, n. Size. Magnitude being purely relative, nothing is large and nothing small. If everything in the universe were increased in bulk one thousand diameters nothing would be any larger than it was before, but if one thing remained unchanged all the others would be larger than they had been. To an understanding familiar with the relativity of magnitude and distance the spaces and masses of the astronomer would be no more impressive than those of the microscopist. For anything we know to the contrary, the visible universe may be a small part of an atom, with its component ions, floating in the life-fluid (luminiferous ether) of some animal. Possibly the wee creatures peopling the corpuscles of our own blood are overcome with the proper emotion when contemplating the unthinkable distance from one of these to another.

Matter moves, but Ether is strained.

MOLECULE, n. The ultimate, indivisible unit of matter. It is distinguished from the corpuscle, also the ultimate, indivisible unit of matter, by a closer resemblance to the atom, also the ultimate, indivisible unit of matter. Three great scientific theories of the structure of the universe are the molecular, the corpuscular and the atomic. A fourth affirms, with Haeckel, the condensation or precipitation of matter from ether—whose existence is proved by the condensation or precipitation. The present trend of scientific thought is toward the theory of ions. The ion differs from the molecule, the corpuscle and the atom in that it is an ion. A fifth theory is held by idiots, but it is doubtful if they know any more about the matter than the others.

My theory of electrical forces is that they are called into play in insulating media by slight electric displacements, which put certain small portions of the medium into a state of distortion which, being resisted by the elasticity of the medium, produces an electromotive force ... I suppose the elasticity of the sphere to react on the electrical matter surrounding it, and press it downwards.
From the determination by Kohlrausch and Weber of the numerical relation between the statical and magnetic effects of electricity, I have determined the elasticity of the medium in air, and assuming that it is the same with the luminiferous ether I have determined the velocity of propagation of transverse vibrations.
The result is
193088 miles per second
(deduced from electrical & magnetic experiments).
Fizeau has determined the velocity of light
= 193118 miles per second
by direct experiment.
This coincidence is not merely numerical. I worked out the formulae in the country, before seeing Webers [sic] number, which is in millimetres, and I think we have now strong reason to believe, whether my theory is a fact or not, that the luminiferous and the electromagnetic medium are one.

No known theory can be distorted so as to provide even an approximate explanation [of wave-particle duality]. There must be some fact of which we are entirely ignorant and whose discovery may revolutionize our views of the relations between waves and ether and matter. For the present we have to work on both theories. On Mondays, Wednesdays, and Fridays we use the wave theory; on Tuesdays, Thursdays, and Saturdays we think in streams of flying energy quanta or corpuscles.

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.

One word characterises the most strenuous of the efforts for the advancement of science that I have made perseveringly during fifty-five years; that word is failure. I know no more of electric and magnetic force, or of the relation between ether, electricity and ponderable matter, or of chemical affinity, than I knew and tried to teach to my students of natural philosophy fifty years ago in my first session as Professor.

Our knowledge of the external world must always consist of numbers, and our picture of the universe—the synthesis of our knowledge—must necessarily be mathematical in form. All the concrete details of the picture, the apples, the pears and bananas, the ether and atoms and electrons, are mere clothing that we ourselves drape over our mathematical symbols— they do not belong to Nature, but to the parables by which we try to make Nature comprehensible. It was, I think, Kronecker who said that in arithmetic God made the integers and man made the rest; in the same spirit, we may add that in physics God made the mathematics and man made the rest.

Proposition IX. Radiant light consists in Undulations of the Luminiferous Ether.

See, thro' this air, this ocean, and this earth,
All matter quick, and bursting into birth.
Above, how high progressive life may go!
Around, how wide! how deep extend below!
Vast chain of being, which from God began,
Natures ethereal, human, angel, man,
Beast, bird, fish, insect! what no eye can see,
No glass can reach! from Infinite to thee,
From thee to Nothing—On superior pow'rs
Were we to press, inferior might on ours:
Or in the full creation leave a void,
Where, one step broken, the great scale's destroy'd:
From Nature's chain whatever link you strike,
Tenth or ten thousandth, breaks the chain alike.

The ether is not a fantastic creation of the speculative philosopher; it is as essential to us as the air we breathe.

The first thing to realise about the Ether is its absolute continuity.

The horrors of Vivisection have supplanted the solemnity, the thrilling fascination, of the old unetherized operation upon the human sufferer. Their recorded phenomena, stored away by the physiological inquisitor on dusty shelves, are mostly of as little present use to man as the knowledge of a new comet or of a tungstate of zirconium … —contemptibly small compared with the price paid for it in agony and torture.

The nature of the atoms, and the forces called into play in their chemical union; the interactions between these atoms and the non-differentiated ether as manifested in the phenomena of light and electricity; the structures of the molecules and molecular systems of which the atoms are the units; the explanation of cohesion, elasticity, and gravitation—all these will be marshaled into a single compact and consistent body of scientific knowledge.

The supposed astronomical proofs of the theory [of relativity], as cited and claimed by Einstein, do not exist. He is a confusionist. The Einstein theory is a fallacy. The theory that ether does not exist, and that gravity is not a force but a property of space can only be described as a crazy vagary, a disgrace to our age.

The work of Planck and Einstein proved that light behaved as particles in some ways and that the ether therefore was not needed for light to travel through a vacuum. When this was done, the ether was no longer useful and it was dropped with a glad cry. The ether has never been required since. It does not exist now; in fact, it never existed.

There is no instrument for measuring the pressure of the Ether, which is probably millions of times greater: it is altogether too uniform for direct apprehension. A deep-sea fish has probably no means of apprehending the existence of water, it is too uniformly immersed in it: and that is our condition in regard to the Ether.

Through radio I look forward to a United States of the World. Radio is standardizing the peoples of the Earth, English will become the universal language because it is predominantly the language of the ether. The most important aspect of radio is its sociological influence. (1926)

To a body of infinite size there can be ascribed neither center nor boundary ... Just as we regard ourselves as at the center of that universally equidistant circle, which is the great horizon and the limit of our own encircling ethereal region, so doubtless the inhabitants of the moon believe themselves to be at the center (of a great horizon) that embraces this earth, the sun, and the stars, and is the boundary of the radii of their own horizon. Thus the earth no more than any other world is at the center; moreover no points constitute determined celestial poles for our earth, just as she herself is not a definite and determined pole to any other point of the ether, or of the world-space; and the same is true for all other bodies. From various points of view these may all be regarded either as centers, or as points on the circumference, as poles, or zeniths and so forth. Thus the earth is not in the center of the universe; it is central only to our own surrounding space.

To vary the compression of the muscle therefore, and so to swell and shrink it, there needs nothing but to change the consistency of the included ether… . Thus may therefore the soul, by determining this ethereal animal spirit or wind into this or that nerve, perhaps with as much ease as air is moved in open spaces, cause all the motions we see in animals.

We believe that each molecular vibration disturbs the ether; that spectra are thus begotten, each wavelength of light resulting from a molecular tremor of corresponding wavelength. The molecule is, in fact, the sender, the ether the wire, and the eye the receiving instrument, in this new telegraphy.

When coming to close quarters with a skunk … one has to fear from an encounter; the worst is that effluvium, after which crushed garlic is lavender, which tortures the olfactory nerves, and appears to pervade the whole system like a pestilent ether, nauseating one until sea-sickness seems almost a pleasant sensation in comparison.