138 Mr. J. Davy’s Account of some Experiments on the 
protoxide of antimony was more highly oxidated, gained only 
11.1 grains. Klaproth did not heat his oxide to redness, and 
hence apparently the discordance. From the above result, 
which I have confirmed by repetition of the experiment, oxide 
of bismuth seems to contain 10 per cent, of oxygene and bis- 
muth being as 67.5, the oxygene in the oxide is to the chlorine 
in the butter of bismuth, as 7.5 to 34.2. 
6. On the Relation between the Proportion of Sulphur in the 
Sulphurets , and the Proportion of Chlorine in some of the Com- 
binations of Chlorine and the Metals . 
The last section afforded proofs of the useful application of 
the general analogy of definite proportions in correcting the 
results of chemical analyses. In the present section, it is my 
intention to pursue a little further, the plan that I have adopted 
in the preceding, and to apply another test to the analyses of 
the combinations of the metals and chlorine, by comparing 
some of them with the combinations of the same metals and 
sulphur. 
I was first led to examine the sulphurets of tin on a different 
account. Aurum musivum, it has been observed, is formed 
when stannane is heated with sulphur. According to M. 
Proust, this substance is a sulphuretted oxide of tin. Were 
this opinion correct, an argument might evidently be deduced 
from it, in favour of the existence of oxygene in chlorine. 
To satisfy myself respecting this, I endeavoured to ascertain 
whether any sulphureous acid gas is produced by the decom- 
position of aurum musivum by heat, as it is commonly asserted. 
I heated to redness in a bent luted green glass tube connected 
with a pneumatic mercurial apparatus about 20 grains of 
