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 Tcherkask, 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 Enzeli. 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 Usmey 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 Fucorum 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.