John Kunkel, born in 1630, was the son of an alchemist attached to the Court of the Duke of Holstein. After serving his father for some years, he obtained employment as chemist and pharmacist under the Dukes Charles and Henry, of Lauenburg. He subsequently entered the laboratory at Dresden of John George II., Elector of Saxony, and, after teaching chemistry at the University of Wittenburg, then famous as a medical school, he accepted an invitation to take charge of the glass works and laboratory of the Elector of Brandenburg, at Berlin. The laboratory was burnt down, and then Charles XI. of Sweden called him to Stockholm and ennobled him as Baron von Lowenstiern. He died in Stockholm in 1702. Kunkel’s chief work is his Laboratorium Chymicum, published after his death. It was written in German. In it Kunkel relates how he acquired possession of a knowledge of the manufacture of Baldwin’s phosphorus, and of the phosphorus discovered by Brand—perhaps the most important, as it certainly was one of the most striking, of the chemical discoveries of the seventeenth century. Kunkel did much to liberate chemical literature from the mysticism and obscurity of alchemy. He was scornful of the theories of the adepts, and contemptuous of their tria prima.
I, old man that I am, who have been occupied with chemistry for sixty years, have never yet been able to discover their fixed sulphur, or how it enters into the composition of metals.... Moreover, they are not agreed among themselves respecting the kind of sulphur. The sulphur of one is not the sulphur of the other. To that one may reply that each is at liberty to baptise his child as he likes. I agree: you may even, if you are so disposed, call an ass a cow; but you will never make anyone believe that your cow is an ass.
As to the alkahest he says:—
There has been much discussion concerning this grand natural solvent. Some derive it from the Latin—akali est; others from the two German words all geist (all gas); lastly, others say it is from alles est (that’s all). As to myself, I do not believe in Van Helmont’s universal solvent. I call it by its true name—alles Lügen heist, or alles Lügen ist (it is all a lie).
Kunkel discovered the secret of the manufacture of aventurine glass and of ruby glass by means of the purple of Cassius—a product from gold first obtained by a doctor of medicine of that name in Hamburg. He made observations on fermentation and putrefaction—recognised that alum was a double salt (salduplicatum); described the present method of repairing pure silver, and of parting gold and silver by means of sulphuric acid. He also described the mode of preparing a number of essential oils, detected the presence of stearopten in oils, and discovered nitrous ether.
John Joachim Becher, the son of a Lutheran minister, was born at Speyer in 1635. Owing to the death of his father and the devastation of the family property during the Thirty Years’ War, Becher had a hard struggle with poverty during his youth, and led a restless, wandering life. In 1666 he was Professor of Medicine in the University of Mayence. Subsequently he went to Munich as head of the finest laboratory in Europe, but, quarrelling with the Chancellor of the Bavarian Court, betook himself to Vienna. After a short stay there, he quitted Austria for Holland, and established himself in Haarlem. Here he proposed to the States-General to extract gold from the sand-dunes; but, the project failing, he left for England and visited the Cornish mines. On the invitation of the Duke of Mecklenburg-Güstrow, he returned to Germany. Shortly afterwards (in 1682) he died, in the forty-seventh year of his age. Becher’s name is remembered mainly in connection with his theory of combustion, which, as we shall see, was subsequently developed by Stahl into the theory of Phlogiston—a generalisation which dominated chemistry until near the close of the eighteenth century.
John Mayow, born in Cornwall in 1645, was a practising physician, whose name chiefly lives by virtue of his clear recognition of the substance or principle in the air which is concerned in combustion, the calcination of metals, respiration, and the conversion of venous into arterial blood. This substance, which he found to be contained in saltpetre, he called spiritus igno-aëreus or nitro aëreust. Mayow died at the age of thirty-four. Had he been able to follow up his observations, he might have influenced very materially the development of theoretical chemistry. As it was, he was practically overlooked by his contemporaries, and the real significance of his work was not appreciated until long afterwards.
Nicolas Lemery, also born in 1645, wrote a Cours de Chimie, one of the best text-books of the time, which passed through as many as thirteen editions, and was translated into English, German, Latin, Italian, and Spanish.
In this book he strove, as he says, to express himself clearly, and to avoid the obscurities which were to be found in the authors who had preceded him.
The fine imaginations of other philosophers concerning their physical principles may elevate the spirit by their grand ideas, but they prove nothing demonstratively. And, as chemistry is a science of observation, it can only be based on what is palpable and demonstrative.