the Oxidation of the Metals, Se. 205 
Messrs. Proust and Chenevix found 39°35. 
: 100°'00 mercury. 
Muriate of mercury ‘cone Lene ad 
qeefcur 4°16 oxygen. 
CPCUIW)mserep s uaee ore jeontaere: 
Messrs. Fourcroy and Thenard found 13:97. 
: : 100 OO mercury. 
Oxidated muriate of et : 
: : 8°21 oxygen. 
(corrosive sublimate) ... _? 
28°16 acid. 
The same chemists found 27°39. 
By setting ont from the proportions of the, sulphate of 
lead given by M. Berthier, we easily find those of the other 
sulphates. 
Sulphate of lead, according ie lead. 
, 7°2y oxeyvyen, * 
fol! Berthar. ack oa; are 8 bap 
Neal bees) (lia 
100°00 copper. 
Sulphate of copper ........4 24°57 oxygen. 
127°09 acid. 
Mr. Proust found 128°46. 
100°00 zine. 
Sulphate of zinc ..........5 24°41 oxygen. 
126°26 acid. 
Mr. Tennant found 1:24:41. 
If we wished to determine by experiments the propor- 
tions of the sulphites, we should experience great difficul- 
ties, because they are changed very easily into sulphates ; 
but we may infer them from those of these last salts. 
I have proved in another part of this volume of the Me- 
moirs of the Society, that the sulphuric acid may be reduced 
by heat into two parts in volume of sulphurous gas and one 
of oxygen gas. We. know, moreover, that a sulphite is 
changed into a sulphate without the neutrality clanging. 
Consequently, the capacity of the sulphurous acid is to 
that of sulphuric acid, as the weight of two paris of sul- 
phurous gas: plus one of-oxygen gas is to that of two 
parts of sulpburous gas: 7. e. by adopting the specific gra- 
vity of the oxygen gas by Lavoisier, and that of the sul- 
phurous gas by Kirwan :: 2°583 : 2°076. By multiplying 
therefore the proportion of acid of each sulphate by this 
ratio, (0°8037) we shall have that of every corresponding 
sulphite. 
It is thus that for the sulphite of bist lead. 
7°29 oxygen. 
Ny eR ol dee iy AA ae Pi 30°30 acid. 
Lastly, in order to give still another example of the cal - 
culations to be made in order to determine the proportions of 
the salts of one and the same genus, I shall take the phos- 
phates ; 
