LOGAN, Sir William Edmond, Canadian geologist, born in Montreal, 20 April, 1798 ; died in Wales, 22 June, 1875. His grandfather, James Logan, a native of Stirling, Scotland, settled in Montreal with his family in 1784. After attending a public school in that city, William, in 1814, attended the high-school of Edinburgh, and afterward Edinburgh university, where he was graduated in 1817. In 1818 he entered the mercantile office of his uncle, Hart Logan, of London, and later became a partner in the firm. After a short visit to Canada, where his attention had been directed to the geological characteristics of the country, he went to Swansea, South Wales, as manager of copper-smelting and coal-mining operations, in which his uncle was interested. He remained in charge until shortly after his uncle's death in 1838. During the seven years that he spent in South Wales he devoted himself to the study of the coal-fields of that region, and his minute and accurate maps and sections were adopted by the ordnance geological survey, and published by the government. He was the first to demonstrate that the stratum of clay that underlies coal-beds was the soil in which the coal vegetation grew, and thereby refuted the drift theory of the origin of coal. In 1841 he visited the coal-fields of Pennsylvania and Nova Scotia, and communicated several valuable memoirs on the subject to the Geological society of London. At this time he began the examination of the older palaeozoic rocks of Canada, and in 1842 he was soon placed at the head of the geological survey of Canada, after refusing a highly advantageous offer of a similar place in India. In the course of his investigations upon the rocks of the eastern townships of Lower Canada, which are a continuation of those of New England, Sir William showed that, instead of being primitive azoic rocks, as had been supposed, they are altered and crystallized palaeozoic strata. This fact, which is the key to the geology of northeastern America, had been before suspected, but had not been demonstrated. The rocks that form the Laurentian and Adirondack mountains, previously regarded as unstratified, he found to be disturbed and altered sedimentary deposits of vast thickness. In 1851 Sir William represented Canada in the great exhibition in London, and had charge of the geological collection that had been made by himself, or under his immediate direction. He was also a commissioner from Canada at the industrial exhibition in Paris in 1855, when he received from the imperial commission the grand gold medal of honor, and was created a knight of the Legion of honor. After the accession of the maritime provinces to the Dominion of Canada, he made an elaborate study of the coal-fields of Pietou, Nova Scotia. The results of his labors will be found in the reports of the geological survey of Canada, and in a very complete map of northeastern America, prepared by him with the aid of Professor James Hall. He was knighted in 18,56, and in the same year received from the London geological society the Wollaston palladium medal. He afterward received the Copley medal from the Royal society of London, of which and of many other learned societies he was long a member. Sir William was also for many years one of the corporation of the University of McGill college in Montreal, from which he received the degree of LL. D., and in which he had endowed the chair of geology. He communicated numerous articles to the Geological society of London and to the "American Journal of Science and Arts." His works are found in his "Annual Reports of the Progress of the Canadian Survey," in the "Proceedings of the British Association," and in those of the Geological society. He also contributed to the Geological survey of Great Britain.