324 Further Observations . 
certain quantity of the compound being known, it becomes 
easy to determine the composition of the compound ; for, 
ammonia being formed of three volumes of hydrogen and 
one of azote, and muriatic acid of one volume of hydrogen 
and one of chlorine, it is evident, that for every three volumes 
of chlorine evolved by the decomposition of muriatic acid, 
one volume of azote must be detached fromthe compound ; 
and the weight of chlorine in the compound must be less 
than the weight of the whole quantity of chlorine produced 
by a portion, which is to the azote in the compound as 
295 to 2295, if the relative specific gravities of the two 
gases be considered as 2-697 and 1. 
Two grains of the compound, when exposed at the tem- 
perature of 62° Fahrenheit, and under a pressure of the at- 
mosphere equal to that of 30°1 inches of mercury to strong 
solution of muriatic acid in a proper apparatus, afforded 
3°91 cubic inches of chlorine. 
In another experiment, one grain of the compound af- 
forded 1°625 cubic inch of chlorine. 
In a third experiment, one grain produced only 1°52 cu- 
bic inch. 
In the two last experiments the compound was acted upon 
much more slowly, and the gas generated exposed to a 
much larger surface of solution of muriatic acid, and the 
appearance of a smaller relative proportion of chlorine must 
be ascribed to the absorption of a larger proportion of that 
gas by the liquid acid; and I found by exposing concen- 
trated solution of muriatic acid to chlorine, that it soon. 
absorbed nearly its volume of that gas. 
I attempted to remove the source of error in the experi- 
ment, by using liquid muriatic acid holding chlorine in so- 
lution; but in this case the quickness of the action of the 
compound on the acid was greatly diminished; and it not 
being easy to obtain the point of absolute saturation of the 
acid with chlorine, some of the gas was absorbed in the 
nascent state during its slow production ; and in most of 
my experiments made in this manner, I obtained less chlo- 
rine from a given weight of the compound, than in operat- 
ing on pure solution of muriatic acid. 
Liquid muriatic acid, whether concentrated or diluted in 
its pure state, does not affect the colour of the sulphuric 
solution of indigo; but it, is immediately destroyed by so- 
lutions containing chlorine dissolved in them. The quan- 
tity of solution of indigo, which is deprived of colour by a 
given quantity of solution of chlorine, is directly as the 
proportion of chlorine it contains; and I found that the 
same 
