On definite Proportions. * J ^ 



determination In a salt which falls to powder, as Is required 

 for «uch experiments as these. . i i .„ ^F 



Vtherelo^e dissolved fwe grammes of f-^^^ -'IP^f'f 

 soda in water, and added to U nitrate ot baryta; the pre 

 apitate, when ,gnued, weighed 8-2 gr. answering to ..9 

 or. of sulphuric acid. In a second experunent I '>bta,nccl 

 from the san.e quantity 8M6 gr. ot igmled sulphate ot 

 baryta. According to Bucholz's experiments, I ought to 

 have had but 8-12,5 gr. The d.flerence is not great, but 

 sufficient to cause a considerable variation m the result . 

 Accord.ns to this experiment, the sulphate oj soda consist, 

 of "Sulphuric acid.. 55-76 lOO'^O 



Soda 44-24 79-34 



Five grammes of ignited muriate of soda, dissolved ,n 

 water, and precipitated by niiraie of sdver, gave 1223 g. 

 of fused horn silver. Ro,e obtained trom the same quan u> 

 12-175 in. These 12-23 gr. of horn silver answer to.2 287 

 of muriatic acid ; hence the 7nuriate of soda consists ot 

 Muriatic acid .. 4574 100-000 



Soda 54-26 118-fi27. 



These analyses of the two salts may be submitted to a 

 test in the follovvine manner. According to these experi- 

 ments, 100 parts ot^nuriatic acid are saturated by 179 '^t 

 potass, and by l 18-6-27 of soda: on the other hand \^0p^rr6 

 of sulphuric'acid require 118-35 ot potass and /9-34 ot 

 soda for their saturation ; but 179:1' 8-63= 1 1&-35 : 78-43 , 

 a result which agrees to'erably well with the experiment, 

 but sho^vs that even in these four experiments there mu.l 

 be some error, which causes the difference. 



Ihe 100 parts of sulphuric acid suppose, m 79-34 oi 

 soda, 20-29 of oxygen, that is 25-56 per cent, with 74-4+ 

 of sodium : and 100 parts of muriatic ac.d require, in the 

 11&-627 of soda, 30-49 of oxvgen ; whence I(10 parts or 

 soda must consist of 25-71 "xygen and 74-'^9 sodium. 



These experiments do not indrcd aerce so well together 

 •aui in the case of potass; but still sufficiently to enable us 

 to conclude that we have in some degree approximated to 

 the truth. As I have no reason to prcler one ot these re- 

 6uhs to the other, I shall assume (- in round numbers ) 

 for the component parts of soda, 



SodlL .. 74-.9 (74 Sw.) 100-00 



Oxygen .. 25-71 (26 Sw.) 34-61 



Mr. Davy assigned, in his first investigations, to potass 



4- of oxygen, to soda -^ that Is, 14 and 22 per cent respec- 



iively. In one of his letters he writes to mc. 1 have ex- 



auiivied the composition of soda and potass on a pretty 



