On the Coneine of Geiger- 
241 
great pressure by means of a steel rod acted on by a power- 
ful press; after it is sufficiently compressed, it is taken from 
the mould, and is now in the form of a solid, flat cylinder, or 
disk, of great density, but the molecules have so little cohe- 
sion, that a blow is sufficient to destroy their continuity. 
When a sufficient number of these disks have been made, they 
are heated to redness, in a porcelain furnace; this part of the 
operation lasts for near a day and a half, when the platina has 
been well purified, and above all well washed, as directed 
above, the disks are now malleable and fit for use. 
It is worthy of remark, that however great may have been 
the pressure to which the platina has been exposed, its bulk 
is always diminished by the action of the furnace. A disk of 
platina, which, when taken from the mould is four inches in 
diameter, and 3-4 of an inch thick, loses when heated to 
redness, 3-4 of an inch in diameter, and 1-4 in thickness. 
The platina is then forged into bars, or rolled into plates; if 
the metal has been well purified, these operations require no 
particular attention. 
In the laboratory of the mines, the operations are so carried 
on, that each day a poud of platina may be purified and forg- 
ed into bars. The expenses of producing a pound of forged 
platina, are estimated at about 29 roubles. 
Jour, de Pharm. 
ART. XLIX.— ON THE CONEINE OF GEIGER. By M. Deschamps. 
It was announced in the " Gazette Medicale" for March 
1832, that M. Geiger, Professor in the University of Heidel- 
burg, had succeeded in obtaining the active principle of conium. 
This coneine he described as a volatile alkaloid, united in the 
Vol. T.— No. 3. 31 
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