9$ 



REMARKS ON COMBUSTION. 



jive out caloric 

 and light j i. e 

 fire. 



melted phofphorus is made to combine with lime heated nearly 

 to rednefs. In all probability barytes and ftrontian exhibit 

 the fame phenomenon when combined with melted fulphur 

 or phofphorus ; and fome of the metals when combined with 

 phofphorus. In general then the emiflion of fire accompanies 

 the combination of melted fulphur and phofphorus, with fe- 

 veral of the earths, fixed alkalies and metals, heated previ- 

 oufly to a certain temperature. 



Explanation. To explain the phenomenon we have only to recollect, 1 . 



Fufed fulphur or That the f u i p h U r and phofphorus are in the melted date, and 



phofphorus con- ... . ,. „,, . , 



tain caloric : me- therefore contain caloric as an ingredient. 2. That the al- 

 tal. &c. contain kalies, earths and metals which produce the phenomenon in 

 come Mid in queftion, contain light as an eiTential ingredient. 3. That 

 combination and the fulphuret or phofphuret formed is always in a folid ftate ; 

 thefe three points once cftabliflied, the procefs admits of a 

 very flmple explanation. The fulphur or phofphorus com- 

 bines with the bafe of the metal, earth or alkali ; while at 

 the fame time the caloric to which the fulphur or phofphorus 

 owed its fluidity, combines with the light of the metal, earth, 

 or alkali, and the compound flies off under the form of fire. 

 The procefs re- Thus the procefs is exactly the fame with combuftion, ex- 

 if " cepting as far as regards the produd. The melted fulphur or 

 ^phofphorus acts the part of the Jupporter, while the metal, 

 earth or alkali occupy the place of the combuftible. The firft 

 furniihes caloric, the fecond light, while the bafe of each 

 combines together. Hence we fee that the bafe of fulphurets 

 and phofphurets refembles the bafe of products in being defti- 

 tute of light, the formation of thefe bodies exhibiting the fepa- 

 ration of tire like combuftion, but the product differing from a 

 product of combuftion in being deftitute of oxigen, we may 

 diftinguifh the procefs by the title of femi-combuftion ; indi- 

 cating by the term, that it polTefTes one half of the characle- 

 riftic marks of combuftion, but is deftitute of the other half. 



The only part of this theory which requires proof is, that 

 light is a component part of the earths and alkalies. But as 

 potafh and lime are the only bodies of that nature, which I 

 am certain to be capable of exhibiting the phenomena of femi- 

 combuftion, the proofs muft of neceffity be confined to them. 

 Now that lime contains light as a component part has been 

 long known. Meyer and Pelletier obferved long ago, that 

 when water is poured upon quicklime not only heat but light 

 is emitted. Light is emitted alfo abundantly when fulphuric 

 2 acid 



tion except ia its 

 product 5 



termed femi 

 combuftion. 



Facts to mew 

 that potafh and 

 lime contain 

 light. 



