RHODIUM. 463 



weight in this experiment was 9 grains ; which 

 is, therefore, the water of crystallization in 

 28-625 grains of soda-muriate of rhodium. 



3. 28 '625 grains of soda-muriate of rhodium 

 were dissolved in water, and precipitated by am- 

 monia added very cautiously, and all excess 

 avoided. The yellow oxide obtained weighed 

 7%5 grains. This step of the analysis cost me 

 a great deal of trouble, and was repeated about 

 ten times before I succeeded in separating the 

 whole of the oxide, and collecting it without 

 loss. 



4. The residual liquid, from which the oxide 

 of rhodium had been thrown down, was evapo- 

 rated with great caution to dryness, and the re- 

 sidual salt weighed. The weight did not exactly 

 agree in the different trials ; doubtless, because 

 I applied the heat so cautiously that the whole 

 aqueous portion was not driven off; but the 

 average weight of this saline residual was 14 '5 

 grains. It was a mixture of common salt and 

 sal-ammoniac. Being exposed to a heat suffi- 

 cient to drive off the sal-ammoniac, the residual 

 common salt weighed 7 ''5 grains. Consequently, 

 the loss of weight was 7 grains ; but the weight 

 of an integrant particle of sal-ammoniac is 6*75 

 grains ; for it is composed of 



1 atom muriatic acid 4- '62 5 

 1 atom ammonia 2.125 



6-75 



