REMARKS ON COMBUSTION. 97 



Thefe fafts, together with the exad correfpondence of the Application of 



. . , t r i_ /i- this theory to 



theory given above with the phenomena ot combuition, ren- other fafts# 

 der it fo probable> that I have ventured to propofe it as an 

 additional ftep towards a full explanation of the theory of 

 combuftion. Every additional experiment has ferved to con- 

 firm it more and more *. It even throws light upon many 

 phenomena which have been hitherto coniidered as altogether 

 anomalous, as will be evident from the following obfervations* 



II. In the year 1793, the aflbciated Dutch chemifts drew Ignition pro- 

 the attention of philofophers to a curious phenomenon which fi o^ e f fulphur" 

 accompanies the formation of fome of the fulphurets ; a phe- with a metal, 

 nomenon previoufly noticed by Scheele ; but which they firft 

 defcribed in detail. When eight parts of copper filings, and 

 three parts of flowers of fulphur are mixed together in a glafs 

 receiver, and the veflel placed upon burning coals, the mix- 

 ture melts, a kind of explofion takes place, it becomes fud- 

 denly red hot, and a glow, like that of a piece of red hot char- 

 coal fanned by bellows, rapidly pervades the whole. When 

 this difappears, the mixture is found in the ftate of folid ful* 

 phuret of copper. Iron, lead, tin or zinc, may be fubfti- 

 tuted for copper. The experiment fucceeds whether the vef- 

 fel be filled with air, or with azotic, or hidrogen gas, or even 

 with water or mercury. What is Angular in this experiment 

 is the glowing red heat, or the emiffion of fire which accom- 

 panies the combination of the fulphur and metal. This emif- 

 fion being the fame which takes place during combuftion, the 

 procefs has been confidered as a combuftion, and ftated as 

 fuch by the German chemifts, as an objection to Lavoifier's 

 theory, which fuppofes that oxigen is a neceflary agent in 

 that procefs : while other philofophers have denied that this 

 operation is a combuftion, or that it has any refemblance to 

 that procefs. 



The (ame emiffion of caloric and light> or oi fire, takes or of fulphur 

 place when melted fulphur is made to combine with pot-ath, ™ lth P° tafl J °5 



•II' • mi r r " me > 0r Phof- 



or with lime, in a crucible or glais tube, and hkewife when phorus with 



lime, &c» 



* In the preceding enumeration of facts I have not taken notice 

 of the modifications which the Lavoiferian theory has received from 

 Hntton, Delametherie, Richter, and Brugnatelli j becaufe I fup- 

 l>ofe them iufficiently known. Every one of thefe modifications 

 agrees in fome particulars with the theory given in thi-s Paper, but 

 differs from it in others. 



Vol. II.— June, 1802, H melted 



