232 Experiments in the Oxygenated 
more caution than before; and I always found that 
when the mixture acquired a certain degree of heat, 
an explosion certainly took place, except the retort 
had a pretty wide neck, and the neck was simply in- 
troduced into a receiver with a considerable opening 
in it without any lute; or, put into water, as in the 
last experiment : and, even in this case, I would not 
advise so much of the salt to be used at one time 
as is here mentioned. The small quantity of acid I 
was able to collect in this way, by adapting a loose 
receiver, appeared to be a weak muriatic acid slightly 
oxygenated; it was of a dilute purple colour, which 
disappeared on its being exposed a short time to the 
light; a small piece of iron dropped into it, caused 
it to become transparent immediately. 
It was a matter of much surprise to me to find 
so strong a smell of nitrous gas produced, on de- 
composing this salt with sulphuric acid. Now as 
nitrous gas consists of azot and oxygen, sup- 
posing this to be nitrous gas (for I do not assert 
it to be so, though I should think the smell in this 
instance an almost sufficient criterion) whence comes 
the azot? At first; I thought it might come from 
a decomposition of the alkaline base of the salt; as 
some chemists have imagined the vegetable alkali to 
be composed of lime and azot; in that case, I ex- 
pected the residuum would have been the sulphat 
of lime, but I found it to be chiefly sulphat of pot- 
ash, with a little of the oxygenated muriat that re- 
