On phlogiston. 467 



If half a drachm of the filings of bar u-on, are melted in 

 twenty ounce meafures of pure air, thirteen ounce meafurcs 

 of the air will be abforbed by the iron, which will be con- 

 verted into finery cinder. Half an ounce raeafure of carl)u- 

 nic acid gas avIU be produced. 



Lavoifier tells us, if the iron is pure, no fi::ed air will be 

 obtained; and certainly Dr. iMeftley will not fay, that thir-^ 

 teen ounce meafures of oxygenous gas enter into the ccm- 

 pofition of half an ounce meafurc of fixed air, which mud 

 be the cafe if his theory is true. 



Here then are twelve and a half ounce meafures of pufe 

 air, which cannot be accounted for according to the fyifenx 

 of Dr. Prieftley, and when we fee a fubftance produced, 

 by melting iron in oxygenous gas, refembling the fcales of 

 iron, in every property, and cannot account for the 

 air which difappears but by fuppofing it is imbibed by the 

 iron, can we hefitate to pronounce, that the fcales of iron 

 contain oxygen. 



The Dodlor likewife fuppofes, that if oxygen was lodged 

 in a calx of iron, it would dephlogifticate the muriatic acid 

 which minium inftantly does, and which we grant docs 

 not contain a third as much pure air as a calx of iron. 



To determine if finery cinder would dephlogifticate the 

 muriatic acid, four ounces of the acid, were difiilled upon 

 three ounces of the powdered fcales of iron, without fuccefs. 



An attempt was alfo made to dephlogifticate the acid, 

 by diftilling two ounces of the fulphuric acid, upon three 

 ounces of common fait, and as much of the fcales of iron, 

 without efFe£t. The quantity of oxygen contained in thefe 

 fcales, muft have been feveral hundred ounce meafures. 



Thefe trials however do not invalidate any thing, which 

 has been advanced by the antiphlogiftic chemifts, for the 

 oxygenation of the muriatic acid, does not depend fo much 

 upon the quantity of pure air contained in a calx, as up- 

 on its readinefs to give out this air to the acid ; when the 

 3 P 2 attraclioa 



