442 GOLD, PLATINUM, PALLADIUM, c. 



of gold which 300 grains of gold are capable of 

 forming. 



But an integrant particle of chloride of so- 

 dium weighs 7*5 : and J*5 x 12 = 90. From 

 this it is evident^ that 90 grains of decrepitated 

 common salt are equivalent to 12 atoms of chlo- 

 ride of sodium ; and it has been stated that 300 

 grains of gold are equivalent to 12 atoms of that 

 metal : from this experiment it follows, that 

 the triple salt contains just as many atoms of 

 common salt as it does of gold. 



3. The triple salt of gold crystallizes in long 

 four-sided prisms. It has a beautiful orange co- 

 lour, and is not in the least altered by exposure 

 to the air ; the description of its properties by 

 Figuier is in general exact. 



Analysis. { sna ij p ass over a g rea t many unsuccessful 

 experiments which I made to determine the pro- 

 portions of its constituents, and satisfy myself 

 with describing the process, which was finally 

 successful. Into a very small green glass re- 

 tort, the weight of which had been previously 

 ascertained and marked on it with a diamond, I 

 put 50%5 grains of the crystallized triple salt, 

 quite dry, but still retaining the whole water of 

 crystallization ; the retort was placed on a chof- 

 fer, and kept for two hours completely red hot, 

 while its beak was plunged into a bason, over 

 which was suspended an inverted glass jar filled 

 with a solution of 55 grains of nitrate of silver 



