It is a very remarkable circumstance, and shows clearly that mankind in general had become disgusted with the dogmas of the Galenists, that iatro-chemistry was adopted more or less completely by almost all physicians. There were, indeed, a few individuals who raised their voices against it; but, what is curious and inexplicable, they never attempted to start objections against the principles of the iatro-chemists, or to point out the futility of their hypothesis, and their inconsistency with fact. They combated them by arguments not more solid than those of their antagonists.
During the presidency of Riolan over the Medical College of Paris, that learned body set itself against all innovations. Guy Patin, who was a medical professor in the University of Paris, and a man of great celebrity, opposed the chemical system of medicine with much zeal. In his Martyrologium Antimonii he collects all the cases in which the use of antimony, as a medicine, had proved injurious to the patient. But in the year 1666, the dispute relative to antimony, and particularly relative to tartar emetic, became so violent, that all the doctors of the faculty of Paris were assembled by an order of the parliament, under the presidency of Dean Vignon, and after a long deliberation, it was concluded by a majority of ninety-two votes, that tartar emetic, and other antimonials, should not only be permitted, but even recommended. Patin after this decision pretended no longer to combat chemical medicine; but he did not remain inactive. One of his friends, Francis Blondel, demanded the resolution to be cancelled; but his exertions were unsuccessful; nor were the writings of Guillemeau and Menjot, who were also keen partisans of the views of Patin, attended with better success.
In England iatro-chemistry assumed a direction quite peculiar. It was embraced by a set of men who had cultivated anatomy with the most marked success, and who were quite familiar with the experimental method of investigating nature. The most eminent of all the English supporters of iatro-chemistry was Thomas Willis, who was a contemporary of Sylvius.
Dr. Willis was born at Great Bodmin, in Wiltshire, in 1621. He was a student at Christchurch College, in Oxford, when that city was garrisoned for King Charles I. Like the other students, he bore arms for his Majesty, and devoted his leisure hours to the study of physic. After the surrender of Oxford to the parliament, he devoted himself to the practice of medicine, and soon acquired reputation. He appropriated a room as an oratory for divine service, according to the forms of the church of England, to which most of the loyalists of Oxford daily resorted. In 1660, he became Sedleian professor of natural philosophy, and the same year he took the degree of doctor of physic. He settled ultimately in London, and soon acquired a higher reputation, and a more extensive practice, than any of his contemporaries. He died in 1675, and was buried in Westminster Abbey. He was a first-rate anatomist. To him we are indebted for the first accurate description of the brain and nerves.
But it is as an iatro-chemist that he claims a place in this work. His notions approach nearer to those of Paracelsus than to the hypotheses of Van Helmont and Sylvius. He admits the three chemical elements of Paracelsus, salt, sulphur, and mercury, in all the bodies in nature, and employs them to explain their properties and changes; but he gives the name of spirit to the mercury of Paracelsus. He ascribes to it the virtue of volatilizing all the constituent parts of bodies: salt, on the other hand, is the cause of fixity in bodies; sulphur produces colour and heat, and unites the spirit to the salt. In the stomach there occurs an acid ferment, which forms the chyle with the sulphur of the aliments: this chyle enters into effervescence in the heart, because the salt and sulphur take fire together. From this results the vital flame, which penetrates every thing. The vital spirits are secreted in the brain by a real distillation. The vessels of the testes draw an elixir from the constituent parts of the blood; but the spleen retains the earthy part, and communicates a new igneous ferment to the circulating fluid. On this account the blood must be considered as a humour, constantly disposed to fermentation, and in this respect it may be compared to wine. Every humour in which salt, sulphur, and spirit predominates in a certain manner, may be converted into a ferment. All diseases proceed from a morbid state or action of this ferment; and a physician may be compared to a wine-merchant; for, like him, he has nothing to do but to watch that the necessary fermentations take place with regularity, and that no foreign substance come to derange the operation.
At this period the mania of explaining every thing had proceeded to such a length, that no distinction was made between dead and living bodies. The chemical facts which were at that time known, were applied without hesitation to explain all the functions and all the diseases of the living body. According to Willis, fever is the simple result of a violent and preternatural effervescence of the blood and the other humours of the body, either produced by external causes, or by internal ferments, into which the chyle is converted when it mixes with the blood. The effervescence of the vital spirits is the source of quotidians; that of salt and sulphur produces continued fever; and external ferments of a malignant nature produce malignant fevers. Thus the smallpox is owing to the seeds of fermentation set in activity by an external principle of contagion. Spasms and convulsions are produced by an explosion of the salt and sulphur with the animal spirits. Hypochondriacal affections and hysteria depend originally on the morbid putrifaction of the blood in the spleen, or on a bad fermentescible principle, loaded with salt and sulphur, which unites with the vital spirits and deranges them. Scurvy is owing to an alteration of the blood, which may then be compared to vapid or stale wine. The gout is merely the coagulation of the nutritive juices altered by the acidified animal spirits; just as sulphuric acid forms a coagulum with carbonate of potash.
The action of medicines is easily explained by the effects which they produce on the nourishing principles. Sudorifics are considered as cordials, because they augment the sulphur of the blood, which is the true food of the vital flame. Cordials purify the animal spirits, and fix the too volatile blood. Willis disagrees with the other iatro-chemists of his time in one thing: he recommends bleeding in the greater number of diseases, as an excellent method of diminishing unnatural fermentation.
Dr. Croone, a celebrated Fellow of the Royal Society, was another English iatro-chemist, who attempted to explain muscular motion by the effervescence of the nervous fluid, or animal spirits.
It is not worth while to notice the host of writers—English, French, Italian, Dutch, and German, who exerted themselves to maintain, improve, and defend, the chemical doctrines of medicine. The first person who attempted to overturn these absurd doctrines, and to introduce something more satisfactory in their place, was Mr. Boyle, at that time in the height of his celebrity.
Robert Boyle was born at Youghall, in the province of Munster, on the 25th of January, 1627. He was the seventh son, and the fourteenth child of Richard, Earl of Cork. He was partly educated at home, and partly at Eton, where he was under the tuition of Sir Henry Wotton. At the age of eleven, he travelled with his brother and a French tutor through France to Geneva, where he pursued his studies for twenty-one months, and then went to Italy. During this period, he acquired the French and Italian languages; and, indeed, talked in the former with so much fluency and correctness, that he passed, when he thought proper, for a Frenchman. In 1642, his father’s finances were deranged, by the breaking out of the great Irish rebellion. His tutor, who was a Genevese, was obliged to borrow, on his own credit, a sum of money sufficient to carry him home. On his arrival, he found his father dead; and, though two estates had been left to him, such was the state of the times, that several years elapsed before he could command the requisite sum of money to supply his exigencies. He retired to an estate at Stalbridge, in Dorsetshire.