Dtcompojltion of the Acetlte of Lead, &c. 359 



dtat of oxygen, the Inflammation niuft be inftantaneous, 

 and the products very much oxidated, while the lirata of 

 hydrogen, almoft pure, burning only at the furtace, form 

 durable meteors, the continued inflammation of which gives 

 rile to very different compounds. 



It will perhaps be allced, how the other fubftances, fuch 

 as filex and magnefia, are found in thefe ftones combined 

 with the metals ? I might, in anfwer, mention the height 

 to which earths reduced to an impalpable powder are vo- 

 latilized bv volcanoes, fo as to be carried away by the winds, 

 I might obferve, alfo, that magnefia, foluble in the hydro- 

 fiilphurets, is foluble alfo, in all probability, in fulphurated 

 hydrogen. But, as I have nothing as yet except conjefturcs 

 to offer on this fubjedl, I mull; here flop. 1, however, flatter 

 myfelf that I have done feme fervice, by (hewing that a phse- 

 nomenon, obfervations of which had been rejetled becauie 

 thought impoflible, has received, at lead in part, a plaufible 

 and natural explanation perfe£lly rational ; and that, when 

 placed beyond a doubt, it vnll be arranged among thofe 

 fcries of fa6fs of which fcience is compofed. 



That I might not render the hypothefis complex, I have 

 faid nothing of the different gafes, fuch as fulphurated hy- 

 drojren, carbonated hydrogen, and carbonous oxide, which 

 mull be continually conveyed into the regions of the atmo- 

 fphere by the decompoiition of bodies. The exillence of 

 the firll of thefe gafes explains, however, the pyritous flate 

 of the iron, and the prefence of fulphur in fome one of its 

 parts. 



LXIV. Obfervatiortf on the Decompofition of the Acellle of 

 Leadi by Zinc in the metallic State. Read in the So- 

 ciety of Pharmacy by L, Anthony Planche*. 



I 



N confuhing the difierent authors who have treated on 

 the hidory of nietali', and thoir chemical attion on difierent 

 bodies, we cannot help conlidering zinc as exceedingly va- 

 huble, both on account of its utility in the arts, and the ef- 

 feniial fcrvices which it daily renders to chemiflry. 



C. Fourcroy, who in his Syjhme des ('uvnniffances Chi- 

 mitjues, has colletfed the mod numerous tnd bed atleded 

 fads of this fcience, has defcribcd all its pri)pertics with that 

 elcaTmfj and method which are jieculiar to him. 



'* Fiom the JoW'in! itr Cbir:ic, No. 133. 



A a 4 It 



