14 SOME NEW SALTS OF CADMIUM. 



evaporated over sulphuric acid, — the double salt being exceedingly 

 soluble in water separated only when the solution was reduced to a 

 very small bulk and the crystals formed were not very perfect. They 

 were in the form of distorted octohedra, acquiring from the extension 

 of certain faces a resemblance to a rhombic prism with dihedral ter- 

 minations. The fact that they were octohedra was proved by 

 measurements made by my colleague, Professor Chapman. 

 1.7SS grammes dried between bibulous paper gave : — 



Water 0-096 = 5-36 



Sulphide of cadmium. 0-338 = 14-70 cadmium. 



Iodide ».f silver 2-275 = 68-74 iodine. 



Sulphate of potash 0*4:603= 1T62 potassium. 



1.771 grammes very carefully dried in bibulous paper and afterwards 

 over sulphuric acid, gave : — 



Water 0-876 = 4-94 



Sulphide of cadmium 0-3520 = 1546 cadmium. 



Iodide of silver 2-2675 = 69-17 iodine. 



Sulphate of potash 0*4183 = 10-60 potassium. 



These numbers lead to the formulae KI + Cd I -f 2 H O. 



Cal I II 



K — 1 — 488-94 — 10-67 — 11-62 — 10-60 

 Cd — 1 — 696-77 — 1521 — 14-70 — 15-46 

 I _ 2— 3171-14— 69-21 — 68-74— (S9-1 7 

 HO— 2— 225-00— 4-91— 5 36— 4-94 



4581-85 10000 100-42 100-17 

 An analysi-i of the anhydrous salt made in 1-42 gave the following 

 numbers, agreeing closely with the calculation : — 



Cal 

 K - 11-47 — 11-22 

 Cd — 16-46 — 15-99 

 I _ 72-85 — 72-79 



100-78 100-00 



OadmW'iodide of Sodium. — Iodide of Sodium was prepared by 

 treating a solution of soua with excess of iodine, decomposing by sul- 

 phuretted hydrogen, warming, neutralizing with carbonate of soda and 

 crystallizing. 



The crystals are as described by Mitscherlich, who gives the 

 formula Na I + 4 H O, while Girand found a quantity of water, 

 which would lead to the formula Xa I + 5 II 0. 

 2108 dried in bibulous paper, lost on heating 04393 = 20-83. 



