94 CAVENDISH. 



air is well known to suffer by all the various ways in 

 which it is phlogisticated, and to discover what becomes 

 of the air thus lost or consumed ;" and the author adds, 

 that besides, " determining this fact, they also threw 

 light on the constitution and means of production of 

 dephlogisticated air." Instead of referring to any for- 

 mer observation of his own either in 1766, or subse- 

 quently, on the moisture left by burning inflammable 

 air, he expressly refers to Mr. Warltire's observation of 

 this moisture, as related by Dr. Priestley: and both 

 Mu. Warltire's observation and Dr. Priestley's publica- 

 tion were made in 1781. Upon this observation Mr. 

 Cavendish proceeded to further experiments, with the 

 view of ascertaining " what becomes of the air lost by 

 phlogistication." For this purpose, he introduced a 

 portion of hydrogen gas into a globe or balloon of 

 glass, sufficiently strong to resist the expansive force 

 of the combustion which had often been observed in 

 mines, and also in experiments upon a smaller scale, 

 to produce an explosion. He adapted to the globe 

 two wires of metal, fixing them in air-tight sockets, 

 and bringing their points within a short distance of 

 each other in the inside of the globe ; so that, by an 

 electrical machine, he could send the spark or the 

 shock from the one point to the other, through the 

 gases mixed together in the globe. He found that 

 the whole of the hydrogen gas disappeared by the 

 combustion thus occasioned, and a considerable por- 

 tion also of the common air. Water was, as usual, 

 found in small quantity, and an acid was also formed. 

 He then weighed accurately the air of both kinds 

 which he exposed to the stream of electricity, and he 

 afterwards weighed the liquid formed by the com- 

 bustion ; he found that the two weights corresponded 

 with great accuracy. It was difficult to resist the in- 

 ference that the union of the two airs had taken place ; 

 and it might further have been inferred that the^latent 

 heat which held them in an elastic state had been given 



