m:n j on the Yellow Prussiate of Pvtaxh Cake. 



289 



■Sting <>t* peroxide of iron, weighing (H2 = 1224, which, when reduced 

 to tin; nit.'t;illic state, gives 8-56 per cent. 



4. Estimation of Carbonate of Lime. — The solution filtered from iron, 

 was treated with oxalate of ammonia, which precipitated the lime as 

 oxalate, which, after being burned, gave of CaO C0 3 *36 = -72 per cent. 



The following are the results of the analyses of the entire prussiate 

 cake : — 



Carbonic acid, 921 



Chlorine, 075 



Cyanogen, 4*32 



Soluble, •{ Sulphuric acid, 9*83 



Potassium, 7*46 



Potash, 32-91 



Lime, 4-78 



(Volatile matter, 1800 



Silica, 3-30 



Insoluble, <J Carbonic acid, *30 



Iron and Sulphur, 8*56 



Lime -42 



99-84 



These may be arranged in the following manner : — 



' Carbonate of potash, 29*30 29'22 



Hydrate of potash, 10*93 11-81 



Chloride of potassium, . . . 1*58 



Cyanide of potassium,... 10 95 11*72 



Sulphate of potash, 6*62 



^ Sulphate of lime, 1T42 



Soluble, 



11-42 



Insoluble, < 



r Volatile matter, 18*00 



Iron, ^ g. 56 



Sulphuret of iron, / 



Carbonate of lime, *72 



L Silica, 3-30 



101*38 

 There is an excess, probably, in consequence of the irregular dis- 

 tribution of the organic matter through the different portions used in the 

 analyses. 



Analysis op the Prussiate Cake Refuse. 



After the yellow prussiate has been dissolved out from the black cake, 

 there remains a quantity of carbonaceous matter, iron, &c. known under 

 the name of prussiate refuse. From its great bulk and weight, the 

 M vunmlation of this matter becomes a serious incumbrance to the prus- 



