dlone gi e very Tittle cyanogen. Second, it sitet more 
with the but the prussiate is not ferruginous, hird, 
ammonia “4 then produced in great quantity. Four, the sub- 
stitution of nitre for potash and the addition of clippings or 
scales, (vattitures) increase the production of cyanogen, and 
give a ferro-prussiate. The author has practised this pro- 
cess for two years in the neighborhood of Paris. His meth- 
od as he describes it is as follo aan 
Blood, supposed dry, —- ~ 3 parts. 
- Nitrate of snail shih lig Part. 
of the blood. 
After Hist édapratat dal the Blood it in a ae copper ket- 
tle the serum is pressed out and the clot returned to the ket- 
tle, with the nitre and the’iron. The hu umidity of the blood 
is sufficient to liquefy the salt, so that the mixture becomes 
uniform. It is then’ removed to an air y loft, where the de- 
siccation is completed. The pateeaann of the blood is 
prevented by the nitrate of potash. When completely dry 
it is put into cast iron cylinders, ‘arranged in a reverberatory 
furnace similar to those used for ivory black. The i Rae Fy 
are heated to dull red, or until smoke ceases to be dise 
filtered nroueh a cloth and evaporated ¢ to the thirty-second 
egree of Baumé’s areometer. On cooling, a considerable 
quantity of the bicarbonate of Bash is produced, in well 
formed crystals. The author has not been able to satisfy 
himself with respect to the manner in which this Ma hte pei 
is formed at so high a temperature, since a portion appears 
to be decomposed during the evaporation of the lel, at first, 
but little alkaline, uae oe ch becomes vety sensibly so, by a 
prolonged eva 
-The same prodait is s not obtained when the potash of 
commerce is used. It is probable that the elements of 
the othe acid act an ftapohtant and necessary part in this 
. Operat 
The iohution which has furnished these crystals, contains 
a little sub eg ash and much cyanuret of ferru- 
retted potassium. aa din “ contracted to 34. placed in 
wooden vousets sibs with le In the course of a few 
days a greenish crystalline aie is obtained: these crystals 
are re-dissolved in a fresh quantity of pure ag which 
evaporated to 32 or 33, yield crystal anew.—Lbid. 
