276 Jl^ Snow. — Native Metals. 



the bafe that fupports them. In the laft place, the iron is 

 carried into the lava by a metalliferous fluid, to which 

 C. Patrin afcribes the property of holding metals in a ftate 

 of vapour, and of depofiting them under certain circum- 

 llances, alnioft as fluoric acid gas does filiceous earth. 



Snow of a very bright red colour has fometimes been 

 found on the fummits of the higheft mountains. The mat- 

 ter which colours it, burns with a fmell fimilar to that of a 

 great many vegetable fubftances. Saufliirc, who often coU 

 lefted fuch fnow on the Alps, was induced by this property, 

 as well as by its being found in fummer, and in places where 

 a great many plants were in flower, to confider the colouring 

 matter as the farina of fome plant *. C. Ramond, who found 

 this duft on the fnow of the Pyrenees, having remarked that 

 it is heavier than water, fufpe6led it to be of mineral origin ; 

 and he, indeed, found that it arifes from a decompofition of 

 certain micas. This decompofition requires, without doubt, 

 the conditions mentioned by Saufllire; for C. Ramond found 

 that they are neceflary to the Pyrenees as well as to the 

 Alps. 



The produtSlion of native metals in the interior of mines 

 is one of thofe objefts alfo which have attracted the atten- 

 tion of naturalifts, and which have given rife to a multitude 

 of fyftems. An experiment of C. Gillet-Laumont points 

 out one of the ways in which this produftion may take 

 place. He has fhown us, that by touching or rubbing with 

 zinc or with iron the muriat of filver, that i$ to fay, a com- 

 bination of the oxyd of filver with the muriatic acid, the 

 filver immediately refumes its purity and luflre by giving 

 up its acid to the metal which touches it. But the cir- 

 cumftances neceffary for this reduction, which chemiftry 

 eafily explains, may occur every mpment in the interior of 

 mines. 



We too often accufe the ancients of error when we do not 

 imderftand them. Ariftotle fpeaks of the afpalax as an ani- 

 mal entirely blind. The Romans and the moderns, having 

 tranflated the word afpalax mole, thought themfelves autho- 



* For an account of Mr. Sauffbre's difcovery of red fnow on the Alps, 

 fee the Pliiljorophical Magazine, Vol. III. p. 168. 



