HTSTORY OP PRUSSIATES. %55 



which is in so many respects inferior to the sulphuric and 

 nitric. 



Lixivium of animal charcoal. 



Equal parts of charcoal of blood and carbonate of pot- Prussic Kit- 

 ash, heated to redness in a covered crucible, always afforded vium ' 

 me the richest lixivium. 



Supposing, that the carbonic acid might be an obstacle Not improved 

 to the saturation of the potash, I added lime to the mixture, b ? liuae * 

 but the lixivium was not improved by it. 



I heated red hot, for half an hour, a mixture of 144 grs. 

 of charred blood, with as much carbonate of potash. After 

 lixiviating, 104 grs. were left, 40 having been destroyed. 



These 104 grs. were again treated with 144 of carbonate 

 of potash, and were reduced to 6-2, so that the loss was 

 42. 



The lixivium of each of these was saturated with the so- First lixivium 

 lution of the sulphate of iron of the shops ; and the blue stron g est - 

 produced by the former, after brightening, was double that 

 afforded by the second. 



To ascertain the influence of temperature, I tried three The red heat 

 mixtures of equal parts, The first was kept red hot half must be kept 

 an hour, the second an hour, the third an hour and a quar- 

 ter. The lixivium of the first produced but little blue ; 

 those of the other two a great deal, and nearly in equal quan- 

 tities. These results prove, either that the simple prussiate, 

 which predominates in the lixivia, is preserved amid the car- 

 bonaceous alkaline mass, or that it is reproduced as fast as 

 it is destroyed. 



Powdered charcoal of blood grows moist in the air. By Calcined blood 

 washing, it affords muriate of soda, and carbonate of soda deliquescent. 

 united with a little prussic acid. 



Charcoal of blood lixiviated with potash a second time Exhausted by 

 still affords blue, though but little; a third time, the blue is successive lixi- 

 i mi n i i • n-i • i viations. 



less perceptible; a fourth time, there is none. 1 his char- 

 coal, thus exhausted, and heated red hot, incinerates with i ncmer ated. 

 great facility, and without exhaling any smell of ammonia, 

 as that does which is burned immediately after having been 

 exposed to distillation. It seems as if it became more com- 

 bustible in proportion as it parts with its azote, and ap- 

 proaches 



