tw 
446. " These facts," continues Mr Davy, 
fully to invalidate the conjectures of M. Ritter, with 
regard to the elementary nature of water. He con- 
ceived that he had procured oxygen from water 
without hydrogen, by making sulphuric acid the 
medium of communication at the negative surface ; 
but, in this case, sulphur is deposited* and the oxy- 
gen from the acid, and the hydrogen from the 
water, are respectively repelled, and a new com- 
bination produced *." In support, however, of 
his opinion, M. Ritter has since urged the result 
of another experiment, to which many eminent 
chemists have yielded their assent. He decomposed 
water in two separate glasses, connected v/ith each 
other by a metallic arc, and obtained oxygen at the 
positive, and hydrogen at the negative pole, in the 
usual manner. Deeming it impossible, however, that 
the two corresponding elements, which were extri- 
cated, could be repelled through the substance of 
the metallic arc, he was induced to deny altogether 
the decomposition of the water, and to maintain its 
elementary nature, conceiving that, by its combina- 
tion with positive electricity, it formed oxygen gas, 
and, by its union with negative electricity, it consti- 
tuted hydrogen gas. 
447. The fallacy of the experiment, which led to 
this conclusion, has, however, been clearly detected 
fey Mr Murray. He formed the Galvanic arrange- 
ment employed by Ritter, and observed oxygen and 
hydrogen to be liberated in the respective glasses ; 
but, on a closer examination, he discovered that the 
* Phil. Trans. 1807. 
