SULPHUROUS ACID ON HYPONITRIC ACID. 67 
Such are, so far as I am aware, the only observations which 
have been made on this subject. They appear to agree in esta- 
blishing that the white crystals contain nitrous acid, sulphuric 
acid and water. But as to the proportions, important as the 
determination of this point is, they still leave much doubt, 
which, as we shall see in the sequel, is not very surprising. 
This uncertainty is even increased by the recent progress of the 
science. As yet, the combination of dry sulphurous acid with 
dry hyponitric acid has not been obtained. Is this combination 
possible? We are led to believe that it is, and to class it with 
RMIMIG AED (32 hws wus bteia Se Og: 
Chlorosulphuric acid of Regnault. . SO, + Cl. 
Iodosulphuric acid ........SO,41 
and lastly, 
Nitrosulphuric acid of Pelouze . . . SO, + N O,. 
This hypothesis is sanctioned by M. Dumas. 
It is my intention now to examine these opinions by the in- 
stitution of some new experiments. 
That dry sulphurous acid gas has no action on the red va- 
pours, also dry, is a fact with which chemists have been long ac- 
quainted. But the elasticity of gases is an obstacle to their union : 
it becomes then important to expose these substances to each 
other in the liquid state. To effect this, the following arrange- 
ment was adopted. Mercury and sulphuric acid were intro- 
duced into a small retort M fig. 1., the neck of which was con- 
¥F 
A 
oo. 1S 
é; 
os E 
| OE ” ae 
M4 YY Uff. 
— er “1, yy CL; Vs 
