30 Dr THOMAS THOMSON on some Experiments on Gold. 



In the second case, the salt will be a compound of 



1 atom muriate of barytes, 14-375 

 1 atom water, - - 1*125 



15*500 



The atomic weight and the ultimate elements are the same in 

 both views. The only difference is, that, if the salt be a muriate, 

 one of the atoms of water is decomposed, its oxygen being united 

 to the barium, and its hydrogen to the chlorine. While, accord- 

 ing to the first view, all the oxygen and hydrogen present are unit- 

 ed together, and constitute water. 



But considerable difficulty will be experienced in applying this 

 reasoning to the muriate of gold. If this salt be a chloride, it is 

 obvious, from the experiments stated in this paper, that it is a com- 

 pound of 



2 atoms chlorine, 9 

 1 atom gold, - 25 



34 



The salt contains besides, 5 atoms of water, 5'625 



2 atoms hydrogen, = 0-250 



3 atoms oxygen, S'OOO 



8-875 



Making a total of 8'875, which, added to 34, make 42'875, the 

 atomic weight of the solid salt. But 2 atoms hydrogen, and 3 

 atoms oxygen, cannot unite together, so as to constitute water. 

 Nor, on the supposition that the salt in question is a chloride, can 

 we easily explain the reason why six integrant particles of pro- 

 toxide of iron are necessary to precipitate one atom of gold, nor 

 why the protoxide of iron, when employed to precipitate gold from 

 its solution in muriatic acid, is converted into peroxide. 



