Miscellanies. 475 
water, twenty grains of bitter extract of the particular plant, and 
abont sixty grains of the recently pulverized charcoal ; they were di- 
gested at temperatures from 78° to 86° F*., and examined at inter- 
vals, being compared with similar solutions without the charcoal. 
Wormwood, centaury, gentian, quassia, were not changed ; or- 
ange peel, camomile, yarrow, soapwort, and Iceland moss, lost all 
their bitterness. Endive, rhubarb, &c. &c. were nearly deprived of 
their bitterness. When animal charcoal, freed from phosphate of 
lime, &c., by digestion in muriatic acid, was used in place of vegeta- 
ble charcoal, similar results were obtained. 
19. Combustion of an Alloy of Tin and Lead.—(R. W. Fox.)— 
When tin and lead have been strongly heated together, (in the flame 
of a blowpipe for instance) the alloy continues igaited a considerable 
time after it has been removed from the flame, throwing out numer- 
ous and brilliant ramifications without cessation, till the whole be- 
comes oxidated, if the quantity be small. The addition of gold does 
not impede the process, and it appears to be converted into a purple 
oxide, though I have as yet only slightly examined it. With plati- 
num in combination, the oxidation is more partial, and a porous alloy 
remains, which is easily pulverised. 
The metals may be treated on mica, or any other imperfect con- 
ductor, capable of resisting a high temperature. The resulting ox- 
ides emit a bright light when acted upon by the blowpipe, owing 
probably to the presence of the oxide of tin, which yields an intense 
light, and so does the oxide of zinc ; but the white ashes of the burnt 
leaves of shrubs or trees exceed all other substances, in this respect, 
that am acquainted with, not excepting lime. 
20. Vauquelin’s Process for obtaining Metallic Chromium.—The 
following is his own account of the process. «When attempts are 
made to obtain chromium from the oxide and carbon, they never suc- 
ceed well, whatever the heat employed. Chromic acid is reduced 
With less difficulty, and from 72 parts 24 of metal were obtained. 
e muriate of chromium is the most favorable substance, and the 
following, which is the correct process, has not been yet described : 
Chromate of lead, in very fine powder, is to be digested in four or 
five times its weight of muriatic acid, until all is dissolved. The li- 
quid is to be evaporated to dryness, the residue digested in alcohol, 
which dissolves the chloride of chromium ; the solution evaporated to. 
