190 Miscellaneous Intelligence. 



teen or twenty minutes, at temperatures between 122 and 140 F., 

 then wrung out and immersed at common temperatures, in a weak 

 solution of hydrosulphuret of potassa, it becomes of a fine gold 

 yellow colour, or of lighter or deeper tints, according to the strength 

 of the cadmium solution. This dye is unaltered by sun-light, or 

 weak acid, or alkaline solutions. Wool could not be dyed by means 

 of this substance with the same facility as silk*. 



16. SEPARATION OF ANTIMONY AND TIN. 



The separation of these metals is very difficult, because of the simi- 

 larity existing between them. M . Gay Lussac has for this purpose 

 long successfully used tin as a precipitant of the antimony. The 

 two metals, their weight being known, are supposed to be in solu- 

 tion in muriatic acid. If alloyed, they would be dissolved in muri- 

 atic acid to which small quantities of nitric acid had been succes- 

 sively added. A plate of tin is to be immersed ; and there being 

 muriatic acid in excess, the antimony will soon deposit as a black 

 powder. The effect will not be perfect at common temperatures ; 

 but by applying the heat of a vapour-bath, it will quickly be con- 

 cluded, provided that excess of acid is continued in the liquor. The 

 antimony is then to be well washed and dried on the water-bath. 

 If the two metals are in solution, their weight not being known, 

 one portion should be precipitated by zinc, to give the whole of 

 both metals, and another portion by tin, to give the proportion of 

 antimonyf. 



17. COMPOUND OF BI-CYANIDE OF MERCURY AND IODIDE OF POTAS- 

 SIUM. {By Dr. Apjohn.) 



When solutions of iodide of potassium and bi-cyanide of mercury 

 are mingled and left, a beautiful pearly substance, in very thin four- 

 sided prisms, is formed, very soluble in hot water, but scarcely 

 affected by water at 60. These undergo no change by ammonia, 

 potash, or the carbonated alkalies in solution : muriatic acid renders 

 them bright scarlet, and evolves the odour of prussic acid. When 

 ignited in a crucible, the residue gave an abundant precipitate with 

 tartaric acid. These and other experiments proved that the com- 

 pound contained both the salts added in solution, and upon analysis 

 they were found in the following proportions : 



Bi-cyanide of mercury . . 24.16 



Iodide of potassium . . . 15.47 



And as these numbers are very nearly in the ratio of the equivalent 

 numbers, it appears that a proportional of each proximate element 

 is present. That the substances are not present, as bi-prussiate 

 and hydriodate, is shown by the correspondence of the absolute 

 weights with the estimate above given, and by the fact that, when 



* Annales de Chimie, adv., 433. f Ibid., advi., 222. 



