J. R. Partington

“The Atomic Theory and the Periodic Law have been given prominence, since their neglect unfailingly leads to obscurity and triviality.”

“Gunpowder was known to Roger Bacon and Albertus Magnus about 1250, but... I conclude that both obtained a knowledge of it from Arabic sources.”

“Some recent short publications on Chinese gunpowder and firearms are misleading... I have had valuable assistance from Dr. J. Needham... If the dates of the texts are correct, the discovery of the use of saltpetre in explosives and the development of gunpowder are to be sought in China from the eleventh century. The history of gunpowder is associated with that of saltpetre, no comprehensive account of which was available.”

“The statement of a law of nature involves the formation of a concept, or general idea, in which the likenesses of phenomena are collected, and the differences, in so far as they are not intimately involved in the nature of the case, are eliminated.”

“To a person whose experience has never been brought into relation with the object sulphur, the name signifies nothing; to the scientist... his concept involves the ideas of specific gravity, crystalline form, element, atom, and the like, derived from past experiences. His concept is distinguished from the other by involving... number or quantity.”

“The quantitative investigations of Black on the burning of lime and magnesia alba, in which the balance (previously characterized by the French chemist Jean Rey as "an instrument for clowns") was applied at every turn, led to the rejection of a hypothetical "principle of causticity," and replaced it by a "sensible ingredient of a sensible body," fixed air.”

“The extension of Black's method by the physicist Lavoisier led to the downfall of the purely qualitative theory of phlogiston, and gave to chemistry the true methods of investigation, and its first great quantitative law—the law of conservation of matter.”

“Wenzel and Richter, the latter... of most pronounced mathematical temperament, laid the foundations of stoichiometry, or "the art of measuring the chemical elements".”

“Dalton, the mathematical tutor, following up the lead of Newton, combined the whole of the results of quantitative measurement which had accumulated up to his time, in a comprehensive theory, based on the concept of the chemical atom.”

“There are not wanting, even to-day, chemists who advocate "purely chemical" methods in chemistry, and cannot appreciate the value of physical evidence in conjunction with mathematical calculations. We can only hope that their number is decreasing exponentially with time.”

“From the time when Guldberg and Waage gave quantitative form to the speculations of the physicist Berthollet, a clear conception of chemical equilibrium, in sharp contrast to an anthropomorphic theory of affinity dating back to Hippocrates and Barchausen, has yielded rich and abundant fruit.”

“Disagreement between theory and experiment has proved a most potent agent in broadening theoretical views, and in making clear the necessity for new concepts or hypotheses.”

“It is necessary to guard against a possible danger... of submitting too readily to the result of a so-called "crucial experiment". Very few experiments can, in the nature of things, be really crucial. One so-called "crucial experiment" which decided between Newton's corpuscular theory of light and Huyghens' wave-theory, viz. the relation between the law of refraction and the velocity of light, was not at all decisive.”

“We perceive clearly that theories and hypotheses are not accepted or rejected outright; they have their periods of activity, and then lie dormant for a time, only to be revived in a new form later on.”

“The fundamental materials from which we construct our picture of the universe may appear in different shapes, but there is really very little discontinuity between what seem at first sight very different views.”

“It is clear, however, that the distinguishing mark of the whole development of theoretical chemistry and physics is the elimination of the anthropomorphic elements, especially specific sense-impressions, from the concepts. This process is called by Prof. M. Planck the objectification of the physical system.”

“The earliest applications of chemical processes were concerned with the extraction and working of metals and the manufacture of pottery. ...The irruption of an iron using race or races into Mediterranean sites ...introduced the Iron Age... but many of the oldest arts still survived in almost their original form. The potter, for example, still used nearly the same materials and appliances as Neolithic man.”

“The blue dye indigo was obtained from the indigo plant by the Egyptians more than 4000 years ago. ...The famous and valuable "purple of Tyre" was perhaps first made in Crete in very early times... obtained at great cost... from tiny marine molluscs. ...The scarlet dye mentioned in the Bible was obtained from the kermes insect (hence the name "crimson").”

“A great number of our common ideas and ways of looking at the world were really shaped for us by the Greeks of antiquity, and... incorporated into the scientific knowledge of today. Such ideas as those of matter, force, element, number, space, time, etc., came to us from the ancient Greeks.”

“We find Theophrastus (315 B.C.) describing... the manufacture of white lead... "lead is placed in an earthen vessel over sharp vinegar, and after it has acquired some thickness of a kind of rust... they open the vessels and scrape it off. ...repeating over and over again... til it is wholly gone. What has been scraped off they then beat to a powder and boil with water for a long time, and what at last settles to the bottom is white lead.”

“The Greek chemical treatises contain... a great amount of practical chemical information... fusion, calcination, solution, filtration, crystallization, sublimation and especially distillation; and methods of heating include the open fire, lamps, and the sand and water baths. Nearly all this practical knowledge... the Arabs... derived... from the very source we are now considering.”

“The Alexandrian chemists were very near to a recognition of gases.”

“The Chinese early learned to work in metals; bronze occurs in the 11th-10th centuries B.C., useful iron from about 500 B.C. At a later period they made brass... True porcelain was first made about A.D. 600. They were probably in possession of mercury at an early date, and learnt how to decompose cinnabar into mercury and sulphur, and recompose it from these materials.”