IRIDIUM. 4-7^ 



2. A hundred grains of the crystals were put Analysis or 



. A , , chloride of 



into a small green glass retort, and kept red hot indium. 

 for two hours by means of a charcoal fire. The 

 crystals did not alter their appearance in the 

 least; yet they emitted a perceptible smell of 

 chlorine, and the salt sustained a loss of weight 

 amounting to 2'6&5 grains. The crystals thus 

 treated were completely soluble in water ; they 

 were therefore in a state of a pure anhydrous 

 chloride of iridium. 



3. 82%5 grains of this chloride dried in a red 

 heat were put into a platinum crucible, and ex- 

 posed to the strongest heat which I could raise 

 in a wind furnace. When the crucible was cold, 

 I found that the chloride had been decomposed, 

 and that there remained 37'5 grains of metallic 

 iridium. The loss of weight sustained was there- 

 fore 45 grains, and this loss was obviously occa- 

 sioned by the dissipation of the chlorine. 



This experiment will be more easily under 

 stood if we divide the quantity of chloride em- 

 ployed by ten. 8*25 grains of chloride of iri- 

 dium, when decomposed by heat, lose 4'5 grains 

 of chlorine, and the remaining 3*75 grains consist 

 of metallic iridium. Thus we see that the chlo- 

 ride is composed of 



Iridium . . . 3*75 



Chlorine 4-5 



8.25 



