G26 Foreign and Miscellaneous Intelligence. 



soluble both in water and alkalies. The presence of a salt renders 

 it insoluble, and upon this effect may be founded a process for its 

 preparation. 



The vanadates, when dissolved in water, are decomposed by sul- 

 phuretted hydrogen, and converted into sulfa salts, of a fine red 

 colour. 



The chloride of vanadium is a very volatile, colourless liquid, pro- 

 ducing thick red fumes in the air. The fluoride is sometimes colour- 

 less, sometimes red, but always fixed. Before the blowpipe vana- 

 dium colours fluxes of a fine green colour, in that respect resembling 

 chrome *. See page 562. 



14. 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 consider- 

 able time after it has been removed from the flame, throwing out 

 numerous and brilliant ramifications without cessation, till the whole 

 becomes 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 

 platinum 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 

 oxides 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. 



15. 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 

 succeed 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 favourable 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 liquid is 

 to be evaporated to dryness, the residue digested in alcohol, which 

 dissolves the chloride of chromium ; the solution evaporated to a 

 syrup, and then formed into a ball with sufficient oil, and, if neces- 

 sary, a little charcoal. This being put into a crucible lined with 

 charcoal, and that placed in another containing powdered charcoal, 



* Ann, de Chimie, xlv. 332. 



