Acidity , Dccompofition of Water , and Phlogifion, 327 
clidillution a colourlefs acid liquor, which from the fmell, the 
properties of diflolving filver very readily, and of giving a de- 
flagrating quality to paper foaked in this liquor when fatu- 
rated with alkali, evidently manifefted the prefence of the ni- 
trous acid. But betides the nitrous, which is undoubtedly the 
acid in greateft abundance, I think I may venture to affirm the 
exigence alfo of the marine acid. 
Upon adding to the green liquor a folution of filver in which 
the acid was fuperabundant, the mixture became turbid; and 
when it was boiled, the minute particles collected . and fell to 
the bottom in form of white flocks, which, on expofure to 
light, became dark coloured, and were re-diflolved by volatile 
alkali ; all which appearances are indications of a lima cornea. 
Although thefe appearances left no doubt in my mind of the 
exigence of a marine acid, I am nevcrthelefs much obliged to 
our ingenious philosophical friend Mr. Johnson for reminding 
us, that Mr. Cavendish had alfo ohferved, in the acid pro- 
duced in his experiment of paffing the eleblric fpark through a 
mixture of dephlogifticated and phlogifticated airs, a precipita- 
tion upon adding a folution of filver ; from whiclr, however, 
that molt accurate philolopher would not infer the prefence of 
marine acid, having difeovered that the precipitation might be 
produced by the nitrous acid itfelf, when that acid is much 
phlogifticated. The acid of the green liquor is in fome degree 
phlogifticated, as appears both from the fmell which I per- 
ceived on adding the folution of filver, which, as I have men- 
tioned, contained a fuperabundant acid, and from the green 
colour of tile liquor ; for I have never been able to make any 
but blue or greenifh-blue faturated folutions from copper and 
nitrous acid, although they fometimes appear green from a 
fuperabundant quantity of yellow acid, or from the yellow 
fumes 
