On definite Proportions. 201 



cordinc; to the rule deduced from the experiments on lead, 

 takinojhalf the quantity nf the sulphur, we shall have 12-S 

 for 100 of copper, which take up 23-tJ of sulphur; and 

 this number differs but little froin the number found bv 

 direct experiments. Jn the analysis of the niuriate of 

 copper we shall find a new confirmation of the propriety 

 of this mode of reasoning. 



But before I proceed further in these investigations, T 

 must determine the true proportion of tjie component parts 

 of the muriate of silver, which is of essential importance 

 for pursuing the inquiry. 



VI. Muriate of Silver and of Baryta. 



Rose and Bucholz have examined the«e salts with great 

 apparent accuracy, and their results agree very nearly with 

 each oiher ; at the same time they are by no means correct, 

 'f he error lies in the defective analysis of the salt of baryta. 

 Wenzel has come the nearest to the truth of all those who 

 have made experiments on the subject, and his rcscarclies 

 were performed with a degree of accuracy which was not 

 to be expected from the tiirie in which he lived. He found 

 in 100 parts of muriate of silver, 7-5'33 of silver, 6*4 of 

 oxygen, and 18"27 of muriatic acid. Bucholz and Rose 

 found 75 parts of silver, 7'5 or 7 of oxygen, and 17"5 to 

 17'7J of muriatic acid. 



l.j I took three grammes of pure silver, obtained from 

 the muriate, and kept for some time in fusion in an opea 

 fire, in order to get rid of the carbon ; and I dissolved it in 

 nitric acid, in a small glass flask ; I added pure muriatic 

 acid, and evaporated the mixture to dryness ; an additional 

 quantity of muriatic acid was poured on it, and the mass, 

 when again drierl, was melted in the flask. This colourless 

 hma cornea weighed 3 "93 gr. Consequently 100 parts of 

 silver had taken up 3<-2'7 of oxygen and muriatic acid, and 

 100 parts of the muriate contain 7J'358 of silver. 



2.) From ID grammes, similarly treated, I obtained 

 13-273 of the fusccf muriate. Hence 100 parts of this con- 

 tain 75-3296 of silver. 



3.) Ten gr. of carbonate of baryta vcre dissolved in 

 muriatic acid in a glass flask ; the solution was poured into 

 a djsh of platina, carefully dried and ignited. I thus ob- 

 tained 10-56 gr, of muriate. 



4.) 'Ilie experiment was repeated, leaving the mass to be 

 dried and ignited in the flask; it afforded again 10-56 

 grammes. 



Since 100 parts of the carbonate of baryta contain 78-4 



of 



