82 
MISCELLANY. 
Nicotine. — Mr. Davy described some experiments made by him in re- 
ference to the relative values of Virginian and Irish tobacco. He pro- 
cured nicotine by simply digesting the leaves in potash, and then dis- 
tilling. A liquid possessing uniform qualities passed over. This liquid, 
when acted upon by acids, afforded salts having a sharp, biting taste. 
The effects of this liquid on animals were those of a powerful narcotic. 
He found that one pound of Virginian tobacco was equivalent to two and 
one-third of Irish ; the root containing four or five per cent, of nicotine. 
Ibid. 
Corrosion of Lead Pipes. — Mr. Moor mentioned a curious fact in re- 
ference to the corrosion of lead pipes. The worm of a still used for pre- 
paring medicated waters, was exhibited, which was corroded completely 
through its substance, at points where it had been supported with wood 
and tied with twine. At these places a black substance was formed, 
consisting of oxide and chloride of lead. It was obvious that the effect 
was to be attributed to galvanic action. Ibid. 
Per oxide of Iron.—- Dr. Barker advises the separation of this by means 
of acetate of potash. This salt, when added to a solution of a per salt of 
iron, precipitates the per oxide when this liquid is boiled. It would, he 
thinks, be an excellent mode of separating iron from manganese. 
Ibid. 
Hydrocyanic Jlcid. — Dr. Geoghehan has suggested the advantage of 
employing the double salt of iodide of potassium and bicyanide of mer- 
cury, for the purpose of detecting hydrochloric acid in hydrocyanic acid. 
Sulphuric acid is frequently met with in hydrocyanic acid, but the dis- 
tinction between these two acids is readily made by means of nitrate of 
barytes. The peroxide of mercury, usually employed for testing the 
purity of hydrocyanic acid, is ambiguous in its action, as it is generally 
impure. The use of this salt is not applicable to the alcoholic hydro- 
cyanic acid. Ibid. 
Ferro-cyanate of Quinia. — M. Bertazzi has given the following process 
for obtaining this salt. Take one part of sulphate of quinia, which is to 
be triturated in a glass mortar, so as to reduce it to a very fine powder; 
then add this to one part and a half of ferro-cyanate of potassa dissolved 
in seven parts of boiling water ; after they have been well mixed, pour 
the compound into a vial, and expose it to a sufficient heat to cause ebul- 
lition, shaking it from time to time. The solution lets fall a substance of 
a greenish yellow colour, and of an oily consistence. After decanting the 
fluid, this precipitate is to be well washed in distilled water, and then 
dissolved in concentrated alcohol, and subjected to a heat of about 100° F., 
