JOHANN FRIEDRICH, a German naturalist of some celebrity, was born at Tübingen in 1748. After taking his degree of M.D., he travelled through England and Holland, lecturing on his favourite subjects of botany and natural history, and finally settled at his native town as extraordinary professor of medicine. He afterwards removed to Göttingen in the same capacity, and remained there till his death in 1804. His name is preserved by his edition (the thirteenth) of Linnæus' Systema Naturæ, which, however, is hardly so well known as Cuvier's criticism of it, in which it is described as “an ignorant compilation, useless to the professor, and more likely to mislead the student than to enlighten or instruct him.” In fact, under the pretence of giving a complete list of synonymes, he collected indiscriminately all the names which he found in different authors, without observing whether such a plant, animal, or mineral had been differently designated by different naturalists, so that the same name has often been given to distinct objects. This double error, which constantly recurs throughout Gmelin's work, shows that the too prolific writer had but a very superficial knowledge of his subject, and did not study the book of nature.”

Though these charges of the great French critic are quite true, yet Gmelin's book is acknowledged to possess a certain value, as being the only book which even professes to include all the objects of natural history described up to the year 1790. His other works are not entitled even to that humble praise.

Gmelin, Johann Georg, a distinguished German naturalist, was born Aug. 12, 1709, at Tübingen. Soon after graduating as M.D., at the early age of nineteen, he went to St Petersburg, where, in 1731, he was appointed professor of chemistry and natural history. He was afterwards sent by the Empress Anna, along with G. F. Müller and a scientific party, to explore Siberia, which he penetrated as far as the Lena. After an absence of nine years and a half, Gmelin returned to St Petersburg, and published his Flora Sibirica. On revisiting Germany in 1747 he was chosen professor of chemistry at Tübingen, where he died in 1755, not long after the publication of his Reise durch Sibirien, or Travels in Siberia. Linnaeus named a genus of Asiatic plants Gmelina in honour of him.

Gmelin, Samuel Gottlieb, nephew of the preceding, was born at Tübingen in 1745. Like his uncle, he graduated as M.D. at the age of nineteen, but instead of practising medicine, he devoted himself to natural science. In 1766 he went to St Petersburg, and obtained leave from Catherine II. to join a scientific expedition then on the point of setting out to explore the S.E. possessions of the Russian empire. Departing in June 1768, he wintered at Woronetz, and thence sailed down to Tcherask, the capital of the Cossacks of the Don. In the following year he reached Astrakhan, and explored the lower part of the course of the Wolga. In 1770 he directed his chief attention to the Caspian Sea and those parts of Persia that bordered on it, and wintered at Enzelli. Next year, after visiting the southern shores of the Caspian and the Persian provinces of Ghilan and Mazanderan, he returned to Astrakhan, and wrote out the narrative of his travels. The year 1773 he devoted to the Caspian; and in 1774, when on his way back to Russia, he was seized by Usman Khan, of the Kaitak tribe, as a hostage, and was so ill-used by that chief that he died, June 27, at Achmetschet in the Caucasus. Some of his papers, however, were recovered, and published under the editorial care of the famous Pallas. His principal works are his Historia Focorum iconibus illustrata, St Petersburg, 1768, 4to; Voyages dans différentes parties de l'Empire de Russie, pour faire des Recherches relatives à l'Histoire Naturelle, St Petersburg, 1770, 1774, 1784, in four vols. 4to; several Memoirs in the Collections of the Society of Haarlem, and of the Academy of St Petersburg.