44-* Additional Notes. 



' Dr. GiBBES, of Great-Britain, also adopts u chemical 

 theory of electricity. He supposes that oxygen gas is pro- 

 duced by the union of positive elect r id tjj w'nh yxiiicr; and 

 hydrogen gas by the union of negative electricitij with wa- 

 ter; and that water, uniting in different proportions with the 

 two electricities, is the ponderable part of all the elastic 

 fluids. He asserts that, by the positive electricity ^ metals are 

 oxy dated, and blue vegetable colours reddened ; and also that 

 the acidifying effect of electric commotions in the atmos- 

 phere, on weak fermented liquors, is unquestionable. On the 

 other hand, according to this writer, by negative electricity the 

 vegetable blue is restored, and the oxydated metal revived. 



These circumstances, among others, lead Dr. Gibbes to 

 conclude that, when hydrogen gas is produced by the affu- 

 sion of water on red-hot metal, and the metal is at the s^me 

 time oxydated, a decomposition of fire rather than of X€ater\\2is 

 taken place; that the hot metal has parted with negative elec- 

 tricity, wliich, uniting with a small proportion of the water, 

 lias formed hydrogen gas ; that a greater proportion of the 

 water has united with the positive electricity, and entered, as 

 oxygen gas, into combination with the metal. When the 

 two gases are inflamed together, the spark attracts to itself, 

 in due proportions, the two electricities contained in the two 

 gases, which unite with explosion, and produce fire. The 

 ■water with which they were before combined is of course de- 

 posited. 



The reason why inflammable substances burn in oxygen 

 gas, and not in hydrogen, Dr. Gibbes supposes to be that 

 negative electricity greatly prevails In all inflammable sub- 

 stances. Neither of the gases can be Inflamed separately, 

 because fire depends on the union of the two electricities; 

 and such union cannot be effected unless both are present in 

 due proportion. 



Dr. Gibbes supposes that the further illustration of the 

 effects of the two electricities as chemical agents, will set 

 aside some of the leading doctrines of the Lavoisierian theory, 

 and afford an easy solution of certain phenomena which that 

 theory cannot explain. 



It is a curious fact that Dr. GibBes, in supposing that oxy- 

 gen gas Is produced by the union of positive electricity with 

 water, and that hydrogen gas is produced by the union of 

 negative electricity with water, was anticipated by Dr. 

 Priestley.^ — See his letter to Dr. Woodhouse, Sept. 16, 

 1801, in the Medical Repository ^ vol. v. p. 158. 



