450 GOLD, PLATINUM, PALLADIUM, &C. 



analyzed with accuracy. From the nitromuri- 

 atic solution of platinum it is easy to form tri- 

 ple salts by adding solutions of muriate of potash, 

 muriate of soda, or muriate of ammonia. The 

 triple salts with ^muriates of potash and ammonia 

 are insoluble powders of a fine yellow colour : 

 the triple salt with muriate of soda is soluble, 

 and crystallizes in beautiful rhombic prisms. 

 These salts furnish a method for determining the 

 atomic weight of platinum, to which I had re- 

 course, after a few unsuccessful trials with muri- 

 ate of platinum. 

 Analysis of ]_. Triple muriate of platinum and potash is 



bichloride r 



of platinum an insoluble yellow tasteless powder, and when 

 num. properly dried contains no water of crystalliza- 

 tion. After a number of preliminary trials to 

 enable me to judge how I ought to proceed, and 

 which it is unnecessary to detail, I analyzed the 

 salt in the following manner : 



30*5 grains of it were put into a platinum 

 crucible, and subjected to a heat which was 

 slowly and cautiously raised till the crucible be- 

 came red hot : by this process the platinum was 

 reduced to the metallic state, and the loss of 

 weight sustained amounted to 9 grains, it was 

 owing to the escape of chlorine in the form of 

 gas. If the salt has been overheated, (which 

 happened in some of my first trials) the loss of 

 weight will exceed 9 grains ; but when this hap- 

 pens, the weight of the chloride of potassium 



