394 Scientific LitelUgence. [May, 



site beauty and intensity of colour. Manufacturers would 

 probably shorten their process considerably by dissolving the 

 sulphate of iron in water some months before they use it, and 

 by keeping the solutions in shallow vessels exposed to the action 

 of the atmosphere. 



XI. Hydrocyanate of Ammonia. 



"When prussiate of iron (prussian blue) is exposed to a red 

 heat in a copper tube, and the products received in glass jars 

 standing over mercury, the glass jar becomes coated with trans- 

 parent crystals, having the smell of hydrocyanic acid, and readily 

 soluble in water. When a drop of sulphuric acid is let fall into 

 a concentrated solution of these crystals, an eftervescence takes 

 place, and a strong smell of hydrocyanic acid exhales. When 

 some soda is mixed with the aqueous solution of these crystals 

 and heat applied, a strong smell of ammonia is perceived. 

 Hence I consider the ciystals as hydrocyanate of ammonia. The 

 efiect produced by the solution of these crystals upon diflferent 

 metalline solutions was as follows. It precipitated 



1. Permuriate of iron. Yellow. 



2. Sulphate of copper, White, with a light shade of 



blue. 



3. Nitrate of lead. White, precipitate redissolved 



by nitric acid. 



4. Nitrate of mercury, White, ditto. 



6. Corrosive sublimate, White, redissolved by agitation. 



6. Sulphate of zinc. White, slight. 



7. Muriate of manganese. Ditto, ditto. 



8. Nitrate of silver, White, redissolvedby agitation. 



9. Sulphate of nickel. Greenish, slight. 



10. Sulphate of cobalt, Reddish, ditto. 



These precipitates do not correspond with those indicated by 

 Scheele ; but he made use of hydrocyanic acid ; not hydrocya- 

 nate of ammonia, which is probably the cause of the difierence. 



XII. Kilkenny Coal. 



In the paper which I published last summer on the different 

 species of pit-coal, I was obhged to leave out Kilkenny coal for 

 want of the requisite specimens. I have been lately enabled, by 

 the kindness of a friend, to make up that deficiency. I shall 

 state here the result of my trials to determine the composition of 

 this species of coal. 



Its specific gravity was 1-4354. 



One hundred grains of it, when burned completely in a muffle, 

 left four grains of a reddish-brown light earth, not in the least 

 acted on by acids. 



One hundred grains, when heated for several hours in a 

 covered platinum crucible left 86"7 grs. of coal not in the least 

 altered in its appearance. Hence the loss of weight was proba- 

 bly owing nut to the dissipation of any volatile matter from the 



