Consider the hateful brew compounded with gleaming, deadly white lead whose fresh colour is like milk…. Over the victim’s jaws and in the grooves of the gums is plastered an astringent froth, and the furrow of the tongue turns rough on either side, and the depth of the throat grows somewhat dry, and from the pernicious venom follows a dry retching and hawking, for this affliction is severe; meanwhile his spirit sickens and he is worn out with mortal suffering. His body too grows chill, while sometimes his eyes behold strange illusions or else he drowses; nor can he bestir his limbs as heretofore, and he succumbs to the overmastering fatigue.

If to be the Author of new things, be a crime; how will the first Civilizers of Men, and makers of Laws, and Founders of Governments escape? Whatever now delights us in the Works of Nature, that excells the rudeness of the first Creation, is New. Whatever we see in Cities, or Houses, above the first wildness of Fields, and meaness of Cottages, and nakedness of Men, had its time, when this imputation of Novelty, might as well have bin laid to its charge. It is not therefore an offence, to profess the introduction of New things, unless that which is introduc'd prove pernicious in itself; or cannot be brought in, without the extirpation of others, that are better.

It is certain that as a nation we are all smoking a great deal too much ... Smoking among boys—to whom it cannot possibly do any kind of good, while it may do a vast amount of active harm—is becoming prevalent to a most pernicious extent. ... It would be an excellent thing for the morality of the people could the use of “intoxicants and tobacco” be forbidden to all persons under twenty years of age. (1878)

It was found after many troublesome experiments that when the vacuum within the lamp globe was good, and the contact between the carbon and the conductor which supported it sufficient, there was no blackening of the globes, and no appreciable wasting away of the carbons. Thus was swept away a pernicious error, which, like a misleading finger post proclaiming “No road this way,” tended to bar progress along a good thoroughfare. It only remained to perfect the details of the lamp, to find the best material from which to form the carbon, and to fix this material in the lamp in the best manner. These points, I think, I have now satisfactorily settled, and you see the result in the lamp before me on the table.

Study of the patients’ diets was begun in 1915 in an attempt to determine if some sort of dietary deficiency could be found. The similarity of certain symptoms and signs of pernicious anemia to those in pellagra, sprue, and beriberi was appreciated.

The human understanding when it has once adopted an opinion (either as being the received opinion or as being agreeable to itself) draws all things else to support and agree with it. And though there be a greater number and weight of instances to be found on the other side, yet these it either neglects and despises, or else by some distinction sets aside and rejects, in order that by this great and pernicious predetermination the authority of its former conclusions may remain inviolate.

The idea that something in food might be of advantage to patients with pernicious anemia was in my mind in 1912, when I was a house officer at the Massachusetts General Hospital…. Ever since my student days, when I had the opportunity, in my father’s wards at the Massachusetts General Hospital, … I have taken a deep interest in this disease. … Prolonged observation permitted me to become acquainted with the multiple variations and many aspects of the disease, and to realize that from a few cases it was difficult to determine the effect of therapeutic procedures.

The saying often quoted from Lord Kelvin… that “where you cannot measure your knowledge is meagre and unsatisfactory,” as applied in mental and social science, is misleading and pernicious. This is another way of saying that these sciences are not science in the sense of physical science and cannot attempt to be such without forfeiting their proper nature and function. Insistence on a concretely quantitative economics means the use of statistics of physical magnitudes, whose economic meaning and significance is uncertain and dubious. (Even wheat is approximately homogeneous only if measured in economic terms.) And a similar statement would even apply more to other social sciences. In this field, the Kelvin dictum very largely means in practice, “if you cannot measure, measure anyhow!”

What about the magical number seven? What about the seven wonders of the world, the seven seas, the seven deadly sins, the seven daughters of Atlas in the Pleiades, the seven ages of man, the seven levels of hell, the seven primary colors, the seven notes of the musical scale, and the seven days of the week? What about the seven-point rating scale, the seven categories for absolute judgment, the seven objects in the span of attention, and the seven digits in the span of immediate memory? For the present I propose to withhold judgment. Perhaps there is something deep and profound behind all these sevens, something just calling out for us to discover it. But I suspect that it is only a pernicious, Pythagorean coincidence.