SILEX SUBLIMED IN IRON WOtlKS. 



75 



but he, no doubt, relied on the external appearance, for it 

 does not contain an atom of this metal. 



To satisfy himself whether it were really oxide of zinc, Itisnotsolu- 

 Mr. Vanquelin boiled some with diiTerent acids, but none ^^^ '" *'^^''*- 

 of them had any action on it : they did not dissolve an atom,. 

 This led to a doubt of the truth of the assertion of metal- 

 lurgists respectinjj it: and the following experiment con- 

 vinced him, that ttiey were altogether mistai<en. 



Having heated this .^abstance with thrice its weight of TreaJed with 

 caustic poti^sh in a silver crucible, it was completely fused, P°^^-"» 

 and the mass produced was entisely dissolved by water. ^nd muriatic 



The solution supersaturated with very dilute muriatic ^<'-'*^» 

 acid did not become turbid, but was converted into a white 

 transparent jelly by evaporation, which is never the case 

 with zinc. 



When this was perfectly desiccated, and the residuum 

 treated with water, a white powder was obtained, which, 

 when washed and dried, did not differ from the original 

 quantity taken a hundredth and half. 



This powder exhibited all the chas&rters of the purest it was found 

 silex. No other earth existed in the liquor from which it^*^ ^e silex. 

 had been separated, and not even any sensible quantity of 

 oxide of iron. 



The difficulty consisted not in finding the nsture of this How is it se- 

 subsrance, but how it was formed in the cavities of the iron. P-"'^-'^'^' 

 JIow indeed are we to conceive, that the silox, which is 

 always mixed with alumine and lime both in the ores of 

 iron, and in the fluxes employed, should have separated 

 from these earths in a state of such perfect purity, that no 

 perceptible quantity of foreign matter can be discovered 

 with it ? 



The filamentous, and as it were crystallized state of this Appsr-ntly by 

 •I At- .. -1. . J • 1. I Ai sublimation. 



silex announces, that it was converted into vapour by the 



violence of the fire, and afterward ge ,tly condensed in the 

 parts of the furnace that were less hot. 



This wonld prove, not only that silex is volatile at a suf- 

 ficient temperature, but that it is more so than alumine or 

 lime; unless we suppose these two earths to have been 

 riiis^d ^Q a gr^at^r h?ight, which is not probable. 



