When at the age of nineteen, the casual dissection of a colmar, a species of cuttle-fish, induced Cuvier to study the anatomy of the mollusca; and the examination of some fossil terebratulæ, which had been dug up near Fécamp, in June, 1791, suggested to him the idea of comparing fossil with living animals; and thus, as he himself said, "the germ of his two most important labours--the comparison of fossil with living species, and the reform of the classification of the animal kingdom--had their origin at this epoch." ------------------ WATT'S DISCOVERY OF THE COMPOSITION OF WATER. A controversy a good many years ago agitated the philosophical world, as to the discovery of the Composition of Water--whether the merit was due to Watt or Cavendish. One of Watt's letters, dated May 15th, 1784, seems to compress the matter into a nutshell. Writing to his friend, Mr. Fry of Bristol, Mr. Watt says, that "he has had the honour of having had his ideas pirated;" that Dr. Blagden explained his theory to Lavoisier, at Paris; that M. Lavoisier soon after invented it himself; and that "since that, Mr. Cavendish has read a paper to the Royal Society on the same idea, without making the least mention of me." "The one," he continues, "is a French financier, and the other a member of the illustrious house of Cavendish, worth above 100,000_l._ (1,000,000_l._) and does not spend 1000_l._ a year. Rich men may do mean actions; may you and I always persevere in our integrity, and despise such doings." Another important point is, that Watt and Cavendish's papers on the discovery were printed under the sole superintendence of Dr. Blagden, secretary to the Royal Society; that Mr. Watt's paper is printed with the _erroneous date of 1784, in place of 1783_, and that the separate copies of Mr. Cavendish's papers have the _erroneous date of 1783, in place of 1784_. The obvious effect of these two errors was to give Cavendish the priority over Watt; whereas, by written testimony, Watt's theory is proved to have been known to Priestley in 1782.