172 An Account of some Experiments on the 



ference does not really exist, and that there is only one 

 known oxide of bismuth, and that Klaproth's oxide was 

 an hydrated oxide; for I have found that 100 grains of 

 bismuth, converted by nitric acid into oxide, precisely in 

 the same manner as the protoxide of antimony was morie 

 highly oxidated, gained only ll-l grains. Klaproth did 

 not heat his oxide to redness, and hence apparently the 

 discordance. From t|je above result, which I have con- 

 firmed by repetition of the experiment, oxide of bisumth 

 seems toconta-n 10 per cent.oF oxygen, and bismuth being 

 as 67"5j the oxygen 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 Snlphiir in 

 the Sulphurets, and the Proportion of Chlorine in some 

 of the Conihinatioiis 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 })receding, and to apply another tes! 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 dif- 

 ferent account. Aurum n)uslvum, it has been observed, is 

 formed wlien stannane is heated with sulphur. Accordmg 

 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 oxygen in 

 chlorine. To satisfy myself respecting this, 1 endeavoured 

 to ascertain whether any sulphureous acid gas is produced 

 by the decomposition of aurum musivum by heat, as it is 

 comiDonly asserted. I heated to redness in a bent luted 

 green glass tube connected with a pneumatic mercurial 

 apparatus about 20 grains of aurum n)ur-,ivum, prepared by 

 the decomposition of stannane with sulphur ; no more gas 

 was produced than the expansion by heat occasioned, sul- 

 phur sublimed, and a gray sulphuret of tin remained. 

 These results I have several times obtained, and not only ' 

 ^y'nh aurum musivum prepared as the preceding, but with 

 some also made according to Woulfe's process. As no 

 su'Jphureous acid gas was produced, and as sulphur sub- 

 limed, it may be concluded that aurum musivum differs 

 merely from the gray sulphuret in containing a larger 

 quantity of sulphur. My next object was to ascertain tlie 



exact 



