436 CAVENDISH. 



suspected the acid to be the produce of some union 

 between the azote and the oxygen of the atmosphere. 

 He left the process in the hands of a committee of his 

 scientific friends, fellow-members of the Royal Society ; 

 and after some weeks of constantly passing the electric 

 fluid through a limited portion of air, a small quan- 

 tity of liquid was formed, which readily combined 

 with a solution of potash in water sent up through 

 the mercury. This union was found to be common 

 nitre, having all the qualities of that well-known sub- 

 stance. It detonated with charcoal ; it sparkled when 

 paper impregnated with it was burnt; it gave out 

 nitrous fumes when sulphuric acid was poured on it. 

 There could, therefore, no doubt whatever now exist 

 that nitrous acid is composed of the two airs deprived 

 of latent heat, which form our atmosphere; that it is 

 a true oxide of azote. 



The undivided merit of this important discovery has 

 never been denied to Mr. Cavendish. Even Lavoisier 

 could not intrude ; but his avidity to claim a share in 

 all discoveries had been exerted respecting the composi- 

 tion of water, which he asserts in his ' Elements of 

 Chemistry' to have been discovered by himself and Mr. 

 Cavendish about the same time. I have shown clearly 

 in the Appendix to the Life of Mr. Watt, that the dis- 

 covery had been previously communicated to the French 

 philosopher ; but it is worth while to consider the ex- 

 periment upon which he grounded his claim ; and 

 that experiment, when examined, is found wholly 

 insufficient to prove the position, even if it had been 

 contrived and performed before the communication of 

 Watt's and Cavendish's discovery. Of that discovery 



