372 On definite Proportions. 
chemists. T am however disposed to consider the analysis - 
of M. Gay-Lussac as affording a confirmation of my ex- 
periments, although the agreement is not quite perfect. 
a.) Carbonate of the protoxide of lead. Ten grammes 
of well dried carbonate of the protoxide of lead, weighed 
while still warm, were ignited in a small crucible of platina; 
they left 8°35 gr. of the protoxide, and had consequently 
Jost 1°65 of carbonic acid. Now if this acid, as Gay- 
Lussac has determined, contains in 100 parts 72°624 of 
oxygen, we have 119-83 of oxygen for 165 parts. But 
835 of the protoxide of lead contain 59°7 of oxygen, and 
59°7 x 2=119°4. 
b.) Carlonate of baryta consists of 29-1 parts of carbonic 
acid and 77°9 of baryta; the one containing 16°05 of oxy- 
gen, the other 8°14; and 8:14X2=16°98. 
c.) Carbonate of lime consists of 43°6 parts of carbonic 
acid and 56:4 of lime: the one corresponding to 31°66 of 
oxygen, the other to 15°88; and this doubled gives 31°76. 
d.) Carbonate of soda. Ten grammes of pure carbonate 
of soda, dried in the heat of melting tin, dissolved in mu- 
riatic acid, aud dried and ignited in a platina crucible, af- 
forded 10:995 gr. of muriate of soda. Since these contain 
5°8757 gr. of soda, it follows that the carbonate contains 
41-243 per cent. of carbonic acid, answering to 29°95 of 
oxygen, while the soda gives 15°077, twice which is 30°15. 
e.) Supercarbonate of soda. Five grammes of fully sa- 
turated carbonate of soda were dissolved in muriatic acid, 
in a flask which had been weighed, and it was found that 
2°60 gr. of carbonic acid had escaped. The remaining so- 
lution, being dried and ignited, afforded 3°46 gr. of muriate 
of soda, containing 1°85 of soda. Consequently the super- 
carbonate consists of 52 parts carbonic acid, 37 soda, and 
11 water. But 52 parts of carbonic acid contain 37°74 of 
oxygen, and 37 of soda 9:49: and 9:49 x4=37'96. Hence 
it follows that the soda in this salt is combined with twice 
as much carbonic aéid as in the foregoing. 
Jf.) Potass and ammonia also afford two salts in which 
the carbonic acid is combined with the base in the same pro- 
portions. I shall take the carbonate of ammonia as an ex- 
ample. M.Gay-Lussac found, that 100 parts of ammonia 
take up 127°37 of carbonic acid in the-common carbonate, 
and 254°74 in the supercarbonate: but 100 parts of am= 
Monia contain 46°88 of oxygen, which doubled becomes 
93°77, and quadrupled 187°54+ The carbonic acid in the 
former salt contains 92°5 of oxygen, and in the Jatter 185. 
All these experiments therefore, except the first, agree in 
indicating 
ue 
