Jobann Georg Von Zimmermann, a Swiss author, born at Brugg, canton of Bern, Dec. 8, 1728, died in Hanover, Oct. 7, 1795. He was educated at the university of Göttingen, pursuing under the direction of Haller an extremely comprehensive course of study with such zeal that his health became permanently impaired. In 1751 he took the degree of M. D., producing a physiological dissertation on " Irritability," which is still held in esteem. He commenced practice at Bern in 1752, but soon removed to Brugg, and attained the highest rank in his profession. Patients resorted to him from all parts of central Europe, depriving him of leisure for study and research. He became in consequence discontented with his position, and the symptoms of melancholy which had appeared during his residence in Gottingen were gradually developed into hypochondria. He avoided society, and passed his leisure hours in reading or meditation, and during this period published his biography of Haller and the first sketch of his well known work "On Solitude" (Ueber die EinsamTeeit, Zurich, 1755). His deportment in the sick room was invariably cheerful, and amid his deepest fits of despondency he strove to inspire confidence and hope in his patients.

In 1758 appeared his treatise on " National Pride " ( Vom Nationahtolze), which attracted much attention from the clearness and moderation of its views, and was speedily translated into the chief European languages. His work on "Experience in Medicine " ( Von der Erfahrunf) in der Arzneilcunst, 2 vols., 1764; English translation, 2 vols., London, 1782) likewise obtained a European reputation, and was instrumental in procuring for him the offices of aulic councillor and physician to the court of Hanover, to which place he removed in 1768. Excessive employment here brought on an internal disorder requiring a visit to Berlin for an operation in 1771, during which he made the acquaintance of Frederick the Great. After a few months he was restored to health, but domestic afflictions plunged him into a fit of unusual despondency. After a second marriage he succeeded in throwing off in a measure his habitual gloom. He now published his completed work "On Solitude " (4 vols., Leipsic, 1784-'5), which obtained an immense popularity throughout Europe, and is the most matured of all his productions, and that with which his name is now most commonly associated.

Zimmermann attended Frederick the Great during his last illness at Berlin in 1786, and published Weber Friedrich den Grossen und meine Unterredung mit ihm kurz vor seinem Tode (Leipsic, 1788), and Fragmente uber Friedrich den Grossen (3 vols., 1790 et seq.; English translation, "Select Views of the Life, Reign, and Character of Frederick the Great," by Major Neumann, 2 vols., 1792). These works involved him in bitter controversies with public men whose characters he had assailed, and were in general so full of coarse calumny and niendacity as to render it certain that he was entering a more dangerous phase of hypochondriasis, under the influence of which the political movements of the times seemed to him only conspiracies against religion and social order. The French revolution and the ideas propagated by it inspired him with a sort of frenzy; and for the purpose of arresting the republicanism which seemed likely to subvert all existing institutions, he addressed a memoir to the emperor Leopold II., recommending a league of the absolute governments against all revolutionists.

In 1794 he was compelled by physical and mental exhaustion to give up all his occupations. - See Zimmermannh Krankengeschichte, by Wichmann (Hanover, 1796), and Vie de Zimmermann, by S. A. Tissot (Lausanne, 1797; English translation, London, 1797). His autobiography appeared at Hanover in 1791.