204 ON AQUA REGIA AND HYPOSULPHURIC ACID. 
sulphuric acid, red vapours are formed. These vapours, 
on entering into an aqueous solution of chlorine, would re- 
produce hydrochloric acid and nitric acid. 
10. In the present case, therefore, the hydrochloric acid 
must be determined by the process which I have communi- 
cated in another article. 
After these preliminaries, I might pass on to the descrip- 
tion of the apparatus I employed, the process adopted, and 
an infinity of precautions taken, in order accurately to de- 
termine the amount of hydrochloric acid, which was not 
acted upon by the nitric acid, the amount of real acid of 
which having been previously ascertained; the analyses, 
however, instituted with various quantities of substances 
have led to results disagreeing with the theory indicated ; 
this description would, therefore, be useless. Although it 
is true that in similar analyses very considerable losses are 
unavoidable, it is nevertheless a fact, that if the loss amounts 
to more than half an equivalent of hydrochloric acid, the 
cause must be sought after, not in the complication of the 
apparatus, or of the analysis, but in some other circum- 
stance. 
11. As this cause maybe supposed to be the deoxidation 
of the hyponitric acid induced by the action of the hydro- 
chloric acid on it, five grammes of well-dried nitrate of lead 
were heated, and the vapours of hyponitric acid thus dis- 
engaged were directed into 100 grammes of pure and con- 
centrated sulphuric acid. The gaseous hydrochloric acid 
gas was then passed into the acid liquid. A large quantity 
of chlorine was disengaged from a solution of sulphate of 
potassa (10.) To ascertain whether the nitric acid in its 
turn was decomposed by hydrochloric acid, the following 
experiment was made: — 
12. Into a solution of 100 grammes of pure sulphuric 
acid, and 2.1 grammes of hyponitric acid, a current of hy- 
drochloric acid was passed for half an hour, and afterwards 
by the application of heat the hydrochloric acid and chlo- 
