John George, public lecturer on botany and physic at Tubingen, member of the Royal Society of Göttingen, and also of the Academy of Sciences at Stockholm, was born on the 12th of August 1709, at Tubingen, where his father was an apothecary. Such was his diligence whilst at school, that he was qualified to attend the academical lectures at the age of fourteen, and was created doctor of medicine when only nineteen. About this time he paid a visit to the metropolis of the Russian empire, that he might have the pleasure of seeing some of his former teachers; and there he became acquainted with Blumentrost, director of the academy, who introduced him to the meetings of the members, and procured for him a pension. At Petersburg he was so much esteemed, that when he intimated a wish, in 1729, to return to Tubingen, he was honoured with a place amongst the regular members of the academy, and chosen professor of chemistry and natural history in the year 1731. In order to carry into execution a plan which had been formed by Peter the Great, for exploring a passage to China and Japan along the coast of the Russian empire, Gmelin was selected, along with two others, as properly qualified for that undertaking, which had also for its object to ascertain the boundaries of Siberia. The department of natural history was assigned to him; and he had with him and his companions, six students, two draftsmen, two hunters, two miners, four land-surveyors, and twelve soldiers, with a sergeant and drummer. They began their journey on the 19th of August 1733; and in 1736 Steller and a painter joined their society, to assist Gmelin in his arduous labours. By exploring Kamtschatka, they hoped to accomplish their mission in a satisfactory manner, for which purpose Steller proceeded to this place, whilst the rest of the party continued their travels through Siberia. In February 1743 Gmelin returned to Petersburg in safety, after a dangerous journey which lasted nine years and a half, but proved of the utmost importance to various branches of science. He resumed the offices which he had filled before; and having paid a visit, in 1747, to his native country, he was chosen professor, whilst absent, in the room of Bachmeister. But in May 1755, he was seized with a violent fever, which put a period to his valuable life, in the forty-fifth year of his age. He was undoubtedly one of the most eminent botanists of the eighteenth century, and has rendered his name immortal by his Flora Siberica, seu historia plantarum Siberiae, in four parts, large quarto. He determined the boundaries between Europe and Asia, which every geographer has adopted since his day. Through all his works the traces of great modesty, a sacred regard to truth, and the most extensive knowledge of nature, are remarkably conspicuous.

Gmelin, Samuel Theophilus, was born at Tubingen on the 23rd of June 1745. After having taken the degree of doctor in medicine at the age of nineteen, he went to finish his studies at Leyden, where a conformity of tastes for natural history united him with Pallas. Finding himself involved in difficulties, he entertained the idea of embarking as surgeon on board of a vessel bound for the East Indies; but in the mean time, whilst waiting for assistance from his family, he established himself in the little town of Brill. The vicinity of the sea, and some excursions which he made by water in the neighbourhood, afforded him an opportunity of collecting many marine plants, and examining with attention the sea-weeds, and suggested to him the idea of writing their history. He next visited Belgium, and then proceeded to Paris, where he was well received by Adanson, who inspired him with something of his own aversion to the system of Linnæus. After a short stay in his native country, he was, in 1766, called to St Petersburg, there to profess botany. Catherine II., faithful to the plan executed by several of her predecessors, of causing learned men to travel in different parts of the Russian empire, ordered a new expedition of the same description to be undertaken. Gmelin obtained permission to join this expedition; and after having had the honour of being presented to the empress, he set out in the month of June 1768, visited the Valdai Mountains, passed the winter at Woronetz, and descended the Don as far as Tscherkask. Here the frightful picture which was drawn of the journey by the steppes, and along the frontier to the mouth of the Terek in the Caspian Sea, induced him to renounce his first project; and he returned by the ordinary route, as far as Zarizin, in order to proceed to Astrakhan by the Volga. In the years 1770 and 1771 he visited different harbours of the Caspian, and examined with peculiar attention those parts of the Persian provinces bordering upon that sea, of which he has given a circumstantial account in his travels. Actuated by a zeal for extending his observations, he attempted to pass through the western provinces of Persia, which are in a state of perpetual disturbance, and infested by numerous banditti. In this expedition he, in April 1772, quitted Enzelli, a small trading place in Ghilan, upon the southern shore of the Caspian; but, on account of many difficulties and dangers, did not, until the 2d of December 1773, reach Sallian, a town situated at the mouth of the river Koor. He thence proceeded to Baku and Kuba, in the province of Shirvan, where he met with a friendly reception from Ali Feth Khan, the sovereign of that district. But after he had been joined by twenty Uralian Cossacks, and when he was only four days journey from the Russian fortress of Kislar, on the Terek, he and his companions were, on the 5th of February 1774, arrested by order of Usmei Khan, a petty Tartar prince, through whose territories he was obliged to pass. Usmei urged as a pretence for this arrest, that thirty years before several families had escaped from his dominions, and had found an asylum in the Russian territories; adding, that Gmelin should not be released until these families were restored. The professor was removed from prison to prison; and at length, wearied out with continued persecutions, he expired, on the 27th of June, at Achmet-Kent, a village of the Caucasus. His death was occasioned partly by vexation for the loss of several papers and collections, and partly by disorders contracted from the fatigues of his long journey. Some of his papers had been sent to Kislar during his imprisonment, and the others were not without great difficulty rescued from the hands of the barbarian who had detained him in captivity. The arrangement of these papers, which form the fourth volume of his travels, was at first consigned to the care of Guldenstaedt, but upon his death was transferred to the learned Pullas. The works of Gmelin are, 1. Historia Piscorum iconibus illustrata, St Petersburg, 1768, in 4to; 2. 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; 3. Several Memoirs in the Collections of the Society of Haerlem, and of the Academy of St Petersburg. Gmelin was also editor of volumes iii. and iv. of the Hora Sibirica of his uncle.