Intelligence and Miscellaneous Articles. 387 



fully evaporated, deposits small square crystals, of a black colour 

 having also a metallic lustre. 



This salt is unalterable in the air, insoluble in alcohol, slightly 

 soluble in water, to which it imparts a wine-red colour ; it contains 

 no water of crystallization. When heated in a retort it yields am- 

 monia, azote, vapour of iodine, iodiduretted hydriodate of ammonia, 

 and leaves spongy platina to the amount of 23 per cent. 



It was found to consist of 



Two atoms of bi-iodide of platina . . 348 x2 = 696 . . 82-86 



One atom of hydriodate of ammonia = 144 .. 17'14 



840 100-00 

 Hydriodate of Bi-iodide of Platina. — This is prepared by digest- 

 ing, cold, bi-iodide of platina in a dilute solution of hydriodic acid. 

 The acid becomes gradually of a fine red colour by saturation with 

 the bi-iodide, and produces a double compound, which may be ob- 

 tained, regularly crystallized, by evaporation under a bell-glass con- 

 taining lime. The crystals are small, black and acicular, placed 

 obliquely, somewhat similar to fern leaves. It is inodorous, has an 

 acerb and rather styptic taste, but not at all an acid one. The cry- 

 stals become slightly moist and of a reddish colour by exposure to 

 the air, and water dissolves them readily. 



It decomposes very slowly in vacuo, and may be repeatedly eva- 

 porated by heat without altering ; at a higher temperature it decom- 

 poses, giving out ioduretted hydriodic acid and vapour of iodine ; 

 platina is left in powder, but in the form of the crystals before calci- 

 nation. 



This compound, analogous in formation to the hydriodate of bi- 

 iodide of mercury, described by M. Boullay, Jun., appears to be 

 composed of 



One atom of hydriodic acid . . 127 .... 26*73 

 One atom of bi-iodide of platina 348 73*27 



475 100*00 



This hydriodate of iodide of platina is decomposed by the alkaline 

 oxides, and converted into a double iodide. — Ann. de Chim. el de 

 Phys., torn. li. p. 113. 



PEROXIDE OF BISMUTH. 



M. Stromeyer observes that this oxide is but very little known, 

 being scarcely mentioned in chemical works, though long since 

 discovered by MM. Bucholz and lirandes, while analysing an ore 

 of bismuth. Having occasion to separate a mixture of silica and 

 oxide of bismuth, they fused it with potash, and on treating it with 

 water, there remained a powder of an ochre yellow colour, which 

 disengaged chlorine with muriatic acid, but dissolved in it without 

 effervescence after calcination, which diminished its weight : by 

 heatingma crucible with charcoal it was reduced to metallic bismuth. 

 Although these experiments evidently prove the existence of a perox- 

 ide of bismuth incapable of forming combinations with acids, the com- 

 position stated by the discoverers was very improbable, and not in 



3D2 



