7S 
MISCELLANY. 
Jn one instance the author found no less than 51 per cent, of graphite. — 
lb. from Jahrb. fur Prakt. Pharm. 
Pyrophorus from Tartar-emetic. — A very dangerous pyrophorus may 
be produced by igniting tartar-emetic in a closed crucible. In some 
experiments to prepare pure antimony in Prof. Wackenroder's labora- 
tory, several ounces of tartar-emetic were submitted to a slight calcina- 
tion. On emptying the carbonaceous residue, which was still some- 
what warm, from the crucible into a dish, it took fire in a few minutes, 
probably by being breathed upon, and was then suddenly projected about 
the laboratory, forming a shower of fire. — Chem. Gaz. from JLrchiv der 
Pharm. 
Observations on the Ferrocyanide of Potassium — »As the ferrocyanide of 
potassium is decomposed on ignition, into cyanide of potassium and iron, 
Liebig has assumed, that on igniting animal charcoal potash and iron, 
cyanide of potassium alone is formed, and that this is converted into 
ferrocyanide of potassium on extracting the ash with water. If the 
finely-powdered fused mass is digested with spirit, but little cyanide of 
potassium is obtained ; on the other hand, on exhausting it with hot 
water, ferrocyanide of potassium is immediately obtained, and indeed to 
the same amount as when procured from the ash in the ordinary way. 
If the formed cyanide of potassium were capable of dissolving iron, the 
iron extracting-pans ought to be considerably attacked, which however 
is not the case, as they frequently last more than ten years. — lb. from 
Foggendorffs JLnnalen. 
On the Preparation of Hyposulphite of Soda. By M. V. Legrip. — The 
author gives the following as a good and cheap process for the prepara- 
tion of hyposulphite of soda, now so extensively employed in taking 
Daguerreotype images : — 
Take of Subcarbonate of soda . . . 730 parts 
Sulphur . . 45 « 
Water 1500 " 
Mix the sulphur first, with a small quantity of the water, and then add 
the soda dissolved in the remainder of the water. Introduce the mixture 
into two two-necked bottles, which shall not be more than two-thirds 
filled, then, 
Take of Clean iron filings 1,500 parts 
Sulphuric acid, (sp. gr. 1.845) . . . 3,000 » 
Put these into a flask capable of holdiug two or three times the above 
quantity. Allow the mixture to cool, and the first portion of disengaged 
hydrogen to escape, then place the flask on a sand-bath, and by means 
