Vol. 68. J AN.NlVERSAPvY ADDEESS OF THE PRESIDEXT. xHx 



both as an official geologist and as an investigator. He was 

 born on August 17th, 1844, and as the son of an eminent 

 Parisian physician he was from the first placed in surroundings 

 calculated to stimulate his extraordinary mental powers and his 

 love of science. He was educated at the Ecole Polytechnique and 

 at the Ecole des Mines, at both of which he distinguished himself. 

 At the age of 23 he became a member of the Corps des Mines, to 

 which body he belonged until the close of his life. 



In 1887, on the retirement of Jacquot, Michel-Levy succeeded to 

 the Directorship of the Service de la Carte Geologique, a post for 

 which he was eminently fitted, both by his personal influence and 

 his great intellectual capacity. Since that date he has superin- 

 tended the issue of 150 sheets of the geological map of Prance 

 (1 : 80,000), and the cartographical excellence of that great pub- 

 lication is in no small measure due to tlie taste and judgment with 

 which he edited it. He was an indefatiguable field-worker, never 

 so happy as when engaged in surveying in Auvergne, in Morvan, 

 or the Western Alps, and eleven sheets of the Prench map were 

 wholly or partly completed by him. His field-work led to the 

 preparation of some important monographs, of which one of the 

 smallest, that on the Granite of Plammanville, because of the 

 theoretical questions which it raised and the discussions which it 

 provoked, is perhaps the best known. 



But it Avas as a theoretical Mineralogist and as a Petrographer 

 that he earned his best right to lasting fame. The ' Mineralogie 

 Micrographique,' which he produced along with Pouque in 1879, 

 though not so much consulted as it was at one time, cannot be 

 ■denied a position among the great pioneer works of Petrology. 

 All the characteristics of his mind were exemplified in this book : 

 mathematical skill, conciseness and lucidity of expression, complete 

 mastery of the subject within the bounds which he had set himself, 

 and consummate artistic taste in the graphic illustnition of his 

 work. 



Two other books, of which he was joint author, the ' Mineraux 

 des Roches ' (with Prof. A. Lacroix), published in 1888, and the 

 '■ Synthese des Mineraux des Eoches ' (with Prof. Pouque), published 

 in 1882, showed his remarkable powers both as an experimental 

 scientist and as a theoretical mineralogist. Much work has beeii 

 done in both these subjects since that day, but it is very largely 

 a development along the lines laid down by Michel-Levy in these 

 books, and, in the broad sketch of the subject which he traced out, 



