436 POPULAR SCIENCE MONTHLY. 



to the Eoyal Society till January, 1784; and this delay, resulting 

 from his desire to investigate the nature of the acid (nitric) formed 

 on the passage of the electric spark through a mixture of hydrogen 

 and oxygen, containing, as was afterwards found, a little nitrogen, 

 caused his claim to the discovery of the composition of water to be con- 

 tested by no less rivals than the celebrated James Watt and the great 

 French chemist, Lavoisier. The modest, retiring and almost inordi- 

 nately cautious man, whose personal history has just been detailed, has 

 been accused of both incapacity and dishonesty, by men distinguished 

 in letters and science, whose connection with the vexed question gives it 

 an interest apart from its intrinsic merit. 



Though Cuvier, in 1812, as secretary of the French Academy in 

 reading an eloge on Cavendish could say that "his demeanor and the 

 modest tone of his writings procured him the uncommon distinction of 

 never having his repose disturbed either by jealousy or by criticism," 

 Cuvier's distinguished, successor, Arago, in writing the eloge on Watt 

 in 1839, charged that Cavendish learned the composition of water, 

 not by experiments of his own, but by obtaining sight of a letter from 

 Watt to Priestley. The French Academy heard the one side argued, and 

 the British Association in the same year heard Cavendish's vindication 

 delivered by the Eev. W. Vernon Harcourt, the president for that year. 



At the very threshold of the water controversy we encounter a per- 

 plexing dilemma. Two unusually modest and unambitious men, uni- 

 versally respected for their integrity, famous for their discoveries and 

 inventions, and possessed of rare intelligence, are suddenly found 

 standing in a hostile relation to each other, and, although declining to 

 publish their own unquestioned achievements, are seen contending for 

 a single discovery, which the one believes the other to have learned at 

 second hand from the revelations made to a common friend, and 

 which that other accuses his rival of having gathered from a letter 

 that he was allowed to peruse. A misunderstanding such as this would 

 never have occurred had Watt and Cavendish been intimate in 1783. 

 As yet, however, the friendly intercourse which afterwards subsisted 

 between them had not commenced. The one was resident in London, 

 the other in Birmingham, and each was informed of the other's doings 

 by third parties, upon whom mainly though not equally, rests the blame 

 of having occasioned the water controversy. Those in question are : Dr. 

 Priestley, J. A. DeLuc and Sir Charles Blagden, all eminent men of 

 unblemished character. Through the first, knowledge of Cavendish's 

 experiments passed to Watt, and a knowledge of Watt's conclusions to 

 Cavendish; by the second. Watt was informed that Cavendish had 

 deliberately pilfered his theory; and the third, who was Cavendish's 

 assistant, reported the latter's conclusions as well as those of Watt, to 

 Iiavoisier, whom he accused of appropriating the ideas of both English 



