of the investigations of Thenard, Gay-Lussac, Chevreul, Dumas, Balard, and Pelouse. It is said that he hesitated at first between science and music, but was finally attracted to chemistry by the lectures of Dumas; and, on leaving college, he constructed a laboratory at his own expense, and pursued his researches without either master or pupils for nearly nine years. He was not more than twenty years old before he marked his place in science by an original work, the scale of which he enlarged in the following years, exhibiting in it so many proofs of an inventive and clear mind that he was sent to Besançon to organize the newly-created faculty of sciences in that city, and became its dean—at the age of twenty-six years. Here, on invitation of the municipal council, he undertook the analysis of the waters of the river Doubs, and of the numerous springs around the town. Applying new and more exact methods, he ascertained the presence of nitrates and silicates in all the waters—facts which were afterward confirmed by Boussingault, and shown by him to have an important bearing on agriculture. This analytical talent out of the usual line, says M. Pasteur in his funeral eulogy, which was one of the features of Deville's genius, never abandoned him; and, "if you review the field of his persevering labor as a whole, you will find it marked at every step by evidences of a passionate seeking for the most perfect analytical methods. That rigor of analysis, which is the probity of the chemist, . . . Deville communicated to all his pupils, and it may be seen to shine in the labors of all those whom he inspired—of Debray, Troost, Fouqué, Grandeau, Hautefeuille, Gemez, Lechartier, and many others."
In 1851, when thirty-three years old, Deville succeeded Balard in the chair of Chemistry in the Higher Normal School in Paris, where he worked at tasks which have led to the enrichment of wealthy manufacturers, and with an ardor which made the laboratory of this institution a central point of chemical investigation for all Europe as well as for France, for the modest salary of three thousand francs, or six hundred dollars. In 1854 he assumed, in addition to his work here, the duties of a lectureship, which fourteen years later became a full professorship, in the Sorbonne.
M. Deville's first researches were in organic chemistry, and began to attract attention in 1840, when he published a remarkable study of turpentine-oil and various derivatives of the terpenes, the carefully tabulated results of which form the chief basis of our knowledge of the different isomeric states of this group. It was followed in 1842 by a research on toluene, which has had an important bearing in the researches on the aniline colors.
He soon afterward turned away from this branch of the science to devote himself to mineral chemistry, in which, says M. Pasteur, he for thirty years held the scepter in France and Europe.
His first great discovery in this department was announced in 1849, when he demonstrated the existence of anhydrous nitric acid, and de-
