314' Miscellaneous lulelligetice. 



stance, having the following properties: solubility in water, 

 the solution having a pure acid taste, followed by one slightly 

 astringent; exposed to the air it deposited prussian blue, and 

 became green ; it has no odour previous to decomposition, but, 

 when boiled, hydrocyanic acid is evolved, and a white powder 

 is deposited, which becomes blue in the air. If cold water be 

 saturated with the dry snper-hydrocyanate, and the solution be 

 left, small colourless transparent crystals form in it in groups. 

 They appear to contain water, and the conjecture is hazarded, 

 that in these the water replaces the second base of the ferro- 

 prussiates. The white substance previously spoken of appears 

 to contain no water, but to be a dry super-hydrocyanate of pro- 

 toxide of iron. It may be preserved in vessels well closed, but 

 in the air is gradually changed into prussian blue. 



The doublecyanuretsof iron with potassium, barium, and cal- 

 cium, when heated, evolve nitrogen, and the cooled mass, when 

 dissolved in water, separates into quadricarburet of iron, and hy- 

 drocyanates of the other bases; so that the cyanuret of iron only 

 has been decomposed, its nitrogen separated, and the other 

 elements left combined in the carburet. When the dry cyanuret 

 of iron and lead is decomposed by heat, it evolves nitrogen, 

 and a double carburet of iron and lead is left, containing one 

 atom quadricarburet of iron, two atoms quadricarburet of lead. 

 If the salt be moist, the carburet of lead is in part decomposed, 

 and carbonic acid formed. Prussian blue gives, on distillation, 

 water, hydrocyanate of ammonia and carbonate of ammonia, 

 water appearing the whole of the time. After these substances 

 had come over the retort was heated red, and the matter within 

 heated and glowed brilliantly, as with the ferro-prussiate of am- 

 monia. The substance left is a tri-caiburet of iron. Ferro- 

 prussiate of copper produces, on distillation, water, nitrogen and 

 carbonate and hydrocyanate of ammonia; the substance left is 

 a compound of one atom quadricarburet of iron and two atoms 

 bi-carburet of copper. Ferro-prussiate of cobalt yields, by dis- 

 tillation, nitrogen and carburets of the metals. The cyanuret 

 of iron and silver is a true cyanuret ; when distilled it yields 

 cyanogen, nitrogen, silver, and quadricarburet of iron. 



M. Berzelius draws the following conclusions from these 

 experiments: — 1. That the cyanurets of the alcaline metals 

 retain their cyanogen at high temperatures, but that the cya- 

 nuret of iron combined with them is decomposed, producing 

 nitrogen and quadricarburet of iron. 2. The cyanurets of the 

 other and more reducible metals are decomposed by a high 

 temperature. Those which may be obtained perfectly free from 

 water yield nitrogen and double quadricarburets ; those which 

 preserve their water until the moment of decomposition lose a 

 certain quantity of carbon, so that though the iron remoins as 



