PASSAGE OF HYDROGEN THROUGH SOLIDS. 
173 
and two and a half drachms of linseed oil, and the spirit of 
wine evaporated. The residue is to be applied, by means 
of a plaster-machine upon well-sized paper. According to 
the Codex Med. Hamburg., the euphorbium is omitted ; 
four drachms of cantharides are treated with four ounces of 
alcoholised ether, two ounces of elemi, one ounce of balsam 
of tolu, one drachm of balsam of Peru dissolved therein, and 
then mixed with three ounces of resin and one and a half 
ounces of Venice turpentine. The mixture is to be heated 
till the spirit is evaporated, and when it has acquired the 
consistency of treacle, it is to be spread on paper. The Ba- 
den Pharmacopoeia , substitutes resin of mezereon for the can- 
tharides and euphorbium. It is obtained by means of high- 
ly rectified spirit of wine from mezereon bark, and is puri- 
fied by ether. Twenty-four grains of this resin are to be 
mixed with four ounces of lard, six drachms of white wax, 
and four drachms of spermaceti, and the whole melted to- 
gether. Paper is to be coated with it three times. Accord- 
ing to Cerutti, the paper is to be spread over with a mix- 
ture of pitch, resin, wax, and turpentine. The new Pharm. 
Boruss., of 1826, prescribes the preparation of a charta 
resinosa, by spreading pitch on paper. — Pharmaceutisches 
Central- Blatt, June 24, 1S4S. 
ART. XXXV. — PASSAGE OF HYDROGEN THROUGH SOLID 
BODIES. 
M. Louyet states, that if a current of hydrogen gas ema- 
nating from a capillary orifice, be directed against a sheet 
of paper, held a few milimetres from the orifice, so that the 
current be perpendicular to it, the paper is traversed by the 
gas. But the gas is not sifted through, as might have been 
expected ; it passes as a current, and may be inflamed be- 
hind the paper as though nothing intervened between the 
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