1819.] M. Stromej/er's new Details respecting Cadmium. 273 



Acetate of cadmium crystallizes in small prisms, visually dis- 

 posed in stars, which are not altered by exposure to the air, and 

 are very soluble in water. 



Tartrate of cadmium crystallizes in small needles, soft, like 

 wool, and scarcely soluble in water. The oxalate is pulverulent 

 and insoluble. 



The citrate forms a crystalline powder, very little soluble. 



Cadmium combines with sulphur, as with oxygen, in only one 

 proportion. One hundred parts of cadmium take 28" 172 of sul- 

 phur. This sulphuret has a yellow colour, with a shade of orange. 

 When heated, it becomes first brown, and then crimson, but it 

 loses these colours on cooling. It is very fixed in the fire. It 

 begins to melt when it is heated to a white-red. It then crystal- 

 lizes on cooling in transparent, micaceous plates, of the finest 

 lemon-yellow colour. It dissolves even cold in concentrated 

 muriatic acid, with the disengagement of sulphuretted hydrogen 

 gas ; but it is attacked with difficulty even with the assistance of 

 heat, when the acid is diluted. 



Sulphuret of cadmium is formed difficultly by fusing together 

 the metal and sulphur. It is obtained with much greater ease 

 by heating together a mixture of sulphur and oxide of cadmium; 

 or by precipitating a salt of cadmium by sulphuretted hydrogen. 



This sulphuret, from its beauty and the fixity of its colour, as 

 well as from the property which it possesses of uniting well with 

 other colours, and especially with blue, promises to be useful in 

 painting. Some trials made with this view gave the most 

 favourable results. 



Phosphuret of cadmium obtained by combining the metal with 

 phosphorus has a grey colour, and a lustre feebly metallic. It 

 is very brittle, and uncommonly refractory. When put upon a 

 red-hot coal, it burns with a beautiful phosphoric flame, and is 

 converted into a phosphate. Muriatic acid decomposes it, 

 disengaging phosphuretted hydrogen gas. 



Iodine unites with cadmium both in the dry and moist way. 

 We obtain large and beautiful hexahedral tables. These crys- 

 tals are colourless, transparent, not altered by exposure to the 

 air. Their lustre is metallic, approaching to pearly. It melts 

 with extreme facility, and assumes on cooling the primitive 

 form. Exposed to a higher temperature, it is decomposed, and 

 allows iodine to escape. Water and alcohol dissolve it with 

 facility. It is composed of 



Cadmium 100-00 



Iodine 227-43 



• 



Cadmium unites easily with most of the metals, when heated 

 %\ ith them without contact of air, in order to avoid oxidation. 

 Most of its alloys are brittle, and colourless ; but hitherto only 

 a few have been examined with precision. 



The alloy of copper and cadmium is white, with a slight tinge 

 Vol. XIV. N°IV. S 



