those of the stars and planets. After a strict examination of Almanacks and Astrological tables, he imagined he discovered, that putrid diseases had always prevailed at those times. when the planets Mars and Saturn were in conjunction. He therefore inferred, that those two planets emitted very deadly exhalations, which infected the air, and all terrestial productions with a putrescent tendency: when myriads of animalcules were instantly generated; and the Plague, the Small Pox, the Measles, or some other putrid fever became inevitable.

Kircher who was a learned ecclesiastic took great pains to demonstrate this theory, which he conceived to be a most valuable discovery; and his work was dedicated to Alexander VII. the reigning Pope.

Many Italian physicians were convinced by the above proofs, which were also swallowed by Langius*, Hauptman and a crowd of Germans. At length Pfeiffer †, a Prussian professor, and a proselyte to this new doctrine, assured the world from the evidence of his microscope, that the variolous insects were white and pellucid; that they had one head and six hairy legs: but reading

*Langii Christ. Patholog. Anim. et Miscel. Curios. Medic. Variolas ac in primis Epidem. Malig. Verminosas, &c. Sieg. Aug. Pfeiffer, M. D.

the details of their generation, numbers, and activity, makes the flesh to creep.

No one can deny the existence of these insects; which never having been found on the human body preceding the variolous fever but only in the purulent secretion at the latter stage of the disease, ought evidently to be considered as an effect, and not as the cause of the malady. But no objection or refutation of this doctrine being published, and as it was harmless, although the invention of a Jesuit, it soon died away.

In 1663, a species* of chemical theory was invented by the celebrated SYLVIUS. He conceived that Small Pox and Measles proceeded from acrimony, of which three kinds are enumerated; the saline lixivial, the acid, and the mixt. He fixed upon the acid acrimony as the cause of Small Pox; and was of opinion that the menstrual blood was the original source.

He next suspected, that this acid humor lurked in the renal glands, until it was excited by certain procatarctick causes; these were the air, aliments, and terror. But of this theory there is already a superabundance, although formerly it had numerous pastisans in Germany.

* Francis. De Le Boe, Sylvii Opera.

1

Besides the more noted theories, multitudes of others were invented in every medical school by the fertile fancies of youthful graduates. These were unfolded in medical essays, dissertations, and inaugural discourses; they flourished, withered, and fell in annual succession.

CHAP. VII.

THE COLD TREATMENT.-SYDENHAM, BOERHAAVE.

EAR eleven centuries had now elapsed

NEAR

since the Small Pox and Measles had reached Arabia; and in the whole of that time the medical profession had founded their treatment upon visionary speculations. As the mischief arising from the external applications was visible, physicians had learned gradually to abstain from them. But although the hot regimen and sweating medicines were followed by numerous deaths, yet the cause was hid: and the theoretic prepossessions were so strong; that in proportion as the mortality augmented, the injunctions for persevering in that fatal plan became stricter. A revolution at length approached.

In the year 1624, THOMAS SYDENHAM was born at Winford Eagle, in Dorsetshire; and was a student at Oxford at the beginning of the civil wars, when Charles the First took possession of that city.

The University adhered warmly to the royal cause; but Sydenham, being in his principles a parliamentarian, retired to London.

He was there persuaded by Dr. Cox, his intimate friend, to study medicine; and when the war terminated he returned for a short time to Oxford, but graduated at Cambridge.

In London, where he established himself, he rose to the first eminence: but neither the emoluments of his private practice, nor the turbulence of the times in which he lived, hindered his exertions for improving medicine, nor prevented his communicating to the public the useful observations he had made. There is, perhaps, not a disease known at that time, the treatment of which was not ameliorated by his sagacity. These numerous improvements evidently proceeded from the plan he adopted.

His opinion of the mass of medical books may be gathered from a whimsical advice * which, when advanced in years, he gave to Sir Richard Blackmore: who, when a student of physic, requested Sydenham to point out to him what books he should read to qualify him for practice. Sydenham replied, "read Don "Quixote, it is a very good book, I read it "still."

This, perhaps, marked his contempt for those medical writings which were merely speculative; but he had been struck with the wisdom of

* A Treatise upon the Small Pox, by Sir Richard BlackPreface.

more.