220 
PHARMACEUTICAL NOTICES. 
tharidin into an acetate of .the same which is not volatilized at 
ordinary temperatures, and the camphor diminishes the symptoms 
of stranguary which some patients have to endure when the ap- 
plication of blistering plaster is resorted to." 
We do not undertand in what way acetic acid, itself a very 
volatile substance, should be able to fix cantharidin, which our 
author himself properly calls a neutral substance, so as to form 
an acetate. According to Mr. Eedwood, (Pharm. Jour. Oct, 
1841,) acetic acid is not a good solvent for cantharidin and 
the Acetum Cantharidis (Lond. Ph.) owes it rubefacient action 
to the acid chiefly. In reference to the volatility of cantharidin, 
the following experiment shows that this principle is not so volatile 
as some anthers state it to be. 100 grains of powdered cantharides 
was introduced into the bottom of a test tube by means of a tube 
funnel so as not to soil the sides. A large tube with the upper 
end drawn out to a small orifice was placed over the mouth of 
the test tube, whilst the closed end containing the flies projected 
through a tin cover into a vessel of water which was kept boiling 
for six hours. At first the hygrometric water of the flies was 
condensed above and removed, and at the end of the experiment 
a minute deposit of microscopic crystals was observed, not ex- 
ceeding the thirtieth of a grain. This experiment is part of an 
investigation of the subject of cantharides not yet ready for 
publication. 
On Mucilage of G~um Arabic, by George D. Coggeshall. The 
author considers the officinal formula for Mucilage of Gum 
Arabic as nearly useless, in as much as it is rarely followed in the 
practice of extemporaneous pharmacy. He thinks that one 
ounce to seven ounces of water comes near the average practice 
of apothecaries, and intention of physicians, and that the solu- 
tion is better when made from the unpowdered gum with cold 
water, as in the process for syrup of gum. He further remarks, 
" Upon the whole it seems desirable that there should be a uni- 
form strength for the mucilage of gum arabic, prescribed by 
physicians in mixtures, which the officinal preparation evidently 
is not. Our mucilage does not enter into other officinal prepara- 
tions, and if it did, the combination of gum and water had better 
be made in general process, as in our almond mixture." 
We object to Mr. Coggeshall's idea of reducing the strength 
