Mr Hertschei on the Acid. ^ 
phate, while a beautiful orange-red powder remains behind, 
which, digested vnth an additional quantity of acid, is merely 
heightened in its colour by the decomposition of the carbonate it 
contained. It is therefore obvious that the oxide is decom- 
posed, being partly converted into the orange or protoxide, 
while the disengaged oxygen converts part of the sulphurous 
into sulphuric acid. Thus, c denoting copper, S sulphur, and 
O oxygen, we have (the carbonic acid escaping as fast as disen* 
gaged), 
2.(c + 0) + S-(S + 20) 
= |(2c+0)+(S + 20)}+(S+30) 
that is, two atoms of sulphurous acid disengage the carbonic 
from two of the carbonate, producing one atom of sulphite of 
protoxide, and generating one of sulphuric acid, which, in its 
turn expelling the acid jfrom one more atom of the carbonate, 
unites with it« base, forming sulphate of peroxide. Whether 
this be any thing like the true statement of the changes, the fol- 
lowing first approximation to an analysis of the red powder will 
tend to show. 14.1 grains were gently ignited, in a small retort 
of glass tube ; sulphurous acid was disengaged in abundance, 
which was received over mercury, and its purity ascertained. 
Scarcely any perceptible dew was disengaged, and the loss of 
weight was 5.2 grains, consisting in part of a very small quanti- 
ty of the powder itself, carried over by the successive slight ex- 
plosions with which it was decomposed. Orange oxide of cop- 
per remained in the retort. The above composition would re- 
quire 4.34 grains to be thus expelled ; but, as I said before, I 
do not give this as an exact analysis. 
It should appear, then, that sulphurous acid is incapable of 
combining with the peroxide of copper, and that what is usually 
stated as to its forming super and sub salts with that oxide, re- 
quires re-examination. When the sulphited protoxide above 
described is boiled mth sulphur, sulphate is formed, sulphurous 
acid disengaged, and a black powder, consisting probably of sul- 
phuret, remains behind ; but no distinct trace of hyposulphu- 
rous acid could be found. Copper, then, seems to form an ex- 
ception to the production of a hyposulphite by this mode of 
operating. 
