386 Intelligence and Miscellaneous Articles. 



triturated with water holding a portion of bi-iodide of platina in solu- 

 tion, it is not dissolved : a strong solution of chlorine decomposes a 

 small portion of the bi-iodide, the results being bichloride of platina 

 and of iodine, or perchloride of iodine, according to the quantity 

 of chlorine employed. Cold sulphuric acid does not act upon it, 

 but when heated it expels a portion of iodine. 



This bi-iodide being decomposed by heat was found to consist of 



Two atoms iodine 126 x 2 = 252 72*42 



One atom platina = 96 27*58 



348 100-00 



Bi-iodide of platina combines readily with other iodides, and pro- 

 duces crystallizable double compounds of determinate proportions. 

 The bi-iodide of Platina and Potassium maybe prepared by direct 

 means: it is of a fine wine-red colour when dissolved in water. It 

 crystallizes by spontaneous evaporation, in small rectangular paral- 

 lelograms, sometimes terminated with four-sided pyramids ; in this 

 state of aggregation it is deep black, with a metallic lustre. It is 

 always mixed with a small portion of uncombined iodide of potas- 

 sium, which is easily separated by washing with alcohol. This salt 

 is unalterable in the air, soluble in water, and imparting a fine deep 

 red colour to it ; it is nearly insoluble in alcohol. Cold sulphuric acid 

 has no effect upon it, which is remarkable, because it acts strongly 

 at common temperatures upon iodide of potassium when uncom- 

 bined ; the same occurs with the chloride of platina and potassium, 

 which is not altered by cold sulphuric acid. 



The double iodide of platina and potassium is composed of 

 One atom of bi-iodide of platina . . 348 .... 67*7 

 One atom of iodide of potassium. . 166 .... 32*3 



514 100-0 



Bi-iodide of Platina and Sodium. — This salt, obtained by a pro- 

 cess like the preceding, crystallizes by exposure to the air in fine 

 prismatic striated needles : it is of lead gray colour, very soluble 

 in water and alcohol, and the solution is of a wine-red colour. As 

 it was found impossible to free it from a portion of free iodide of 

 sodium, it was not analysed. 



Bi-iodide of Platina and Barium. — This salt has nearly the same 

 properties as the last-mentioned, being deliquescent, but_not in so 

 great a degree. 



Bi-iodide of Platina and Zinc. — This compound is prepared by sa- 

 turating, cold, a solution of iodide of zinc, with bi-iodide of platina: 

 it is very difficult to procure it regularly crystallized, irregular 

 crystals forming in a red syrupy mass : it is very soluble in water, 

 and attracts it strongly from the air ; it has a strong styptic taste, 

 like the other preparations of zinc. 



Hydriodate of Ammonia and Platina. — This double salt, which 

 is analogous to the muriate of ammonia and platina, is prepared by 

 digesting, either cold or in a gentle heat, bi-iodide of platina, in a so- 

 lution of hydriodate of ammonia: the red liquor obtained, when care- 



