GEORGE ERNEST, an eminent German chemist, was born at Ansbach, on the 21st of October 1660, and chosen professor of medicine at Halle, when a university was founded in that city in 1694. The excellency of his lectures while he filled that chair, the importance of his various publications, and his extensive practice, soon raised his reputation to a very great height. He received an invitation to Berlin in 1716, which having accepted, he was made counselor of state and physician to the king. He died in 1734, in the seventy-fifth year of his age. Stahl is without doubt one of the greatest men of which the annals of medicine can boast: his name marks the commencement of a new and more illustrious era in chemistry. He was the author of the doctrine of phlogiston, which, though now completely overturned by the discoveries of Lavoisier and others, was not without its use, as it served to combine the scattered fragments of former chemists into a system, and as it gave rise to more accurate experiments and a more scientific view of the subject, to which many of the subsequent discoveries were owing. This theory maintained its ground for more than half a century, and was received and supported by some of the most eminent men which Europe has produced; a sufficient proof of the ingenuity and the abilities of its author. He was the author also of a theory of medicine, founded upon the notions which he entertained of the absolute dominion of mind over body; in consequence of which he affirmed, that every muscular action is a voluntary act of the mind, whether attended with consciousness or not. This theory he and his followers carried a great deal too far; but the advices at least which he gives to attend to the state of the mind of the patient, are worthy of the attention of physicians.

"Stahl," says Dr. Cullen, "has explicitly founded his system on the supposition, that the power of nature, so much talked of, is entirely in the rational soul. He supposes that, upon many occasions, the soul acts independently of the state of the body; and that, without any physical necessity arising from that state, the soul, purely in consequence of its intelligence, perceiving the tendency of noxious powers threatening, or of disorders anyways arising in the system, immediately excites such motions in the body as are suited to obviate the hurtful or pernicious consequences which might otherwise take place. Many of my readers may think it was hardly necessary for me to take notice of a system founded upon so fanciful a hypothesis; but there is often so much seeming appearance of intelligence and design in the operations of the animal economy, that many eminent persons, as Perrault in France, Nichols and Mead in England, Porterfield and Simson in Scotland, and Gaubius in Holland, have very much countenanced the same opinion, and it is therefore certainly entitled to some regard."

His principal works are, 1. Experimenta et Observationes Chymicae et Physicae, Berlin, 1731, 8vo. 2. Dissertationes Medicae. Halle, 2 vols. 4to. 3. Theoria Medica vera. 1737, 4to. 4. Opusculum Chymico-physico-medicum. 1740, 4to. 5. A Treatise on Sulphur, both Inflammable and Fixed, written in German. 6. Negotium Otiosum. Halle, 1720, 4to. It is in this treatise chiefly that he establishes his system concerning the action of the soul upon the body. 7. Fundamenta Chymiae Dogmaticae et Experimentalis.

Cullen's First Lines of the Practice of Physic, vol. i. p. 12.