Miscellanies. Alb 



water, twenty grains of bitter extract of the particular plant, and 

 about 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. &ic. were nearly deprived of 

 their bitterness. When animal charcoal, freed from phosphate of 

 lime, Sic, 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 ignited 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 I 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. 

 The 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 



