1825.] Mr, Davies on Flame* 447 



Article IX. 



Some Investigations respecting the Nature and Phenomena of 

 Flame, By Mr. John Davies, MWS. 8cc. &c. Lecturer on 

 Chemistry, &c.^ (Communicated by the Author.) 



The important researches of Sir H. Davy on the nature and 

 phenomena of flame have shown that the subject combines 

 interesting speculation with practical utihty. Since the con- 

 trivance of his lamp, and the publication of his admirable 

 investigations connected with it, the inquiry, which had been 

 previously neglected, has excited the attention which it merits. 



I have, therefore, presumed that an account of some results 

 ■which I have obtained on the subject will, like my former 

 papers, be received with indulgence by this Society. 



Flame, or that species of combustion in which light is fur- 

 nished, is produced by the rapid union of a combustible body 

 with a supporter of combustion. 



The cause of inflammation has never been clearly developed. 

 It has, indeed, been ascribed to the agency of electricity ; but 

 this explanation, which is rather fanciful, is liable to the 

 reproach which the President of this Society applied, in one of 

 his late lectures, to certain hasty and fashionable speculations, 

 when he remarked, that we are, in the present day, very apt 

 to refer to the agency of electricity every thing wnich we do 

 not understand. . ;, 



It may, however, be expedient to offer here a brief statement 

 of the hypothesis. 



In most cases of inflammation, hydrogen is the burning 

 body ; and its combustion is effected in general by its union 

 with oxygen. When, however, hydrogen is the only combus- 

 tible present, the inflammation is always feeble ; and in order 

 to obtain a brilliant and powerful flame, carbon seems, in or- 

 dinary cases^ to be indispensable. 



In the instance of a common candle, the hydrogen and part 

 of the carbon are supphed from the decomposition of the 

 tallow ; the remainder, which must be a very small quantity, 

 arises from the wick, and the oxygen is furnished by the 

 atmosphere. An elevation of temperature, such as is pro- 

 duced by a lighted taper, is required to give the first impulse 

 to the combustion ; but afterwards it goes on of itself, because 

 the candle finds a supply of caloric in the successive quantities 

 of heat which, it is conceived, result from the union of the two 

 electricities given out by the gases during their combustion. 

 This explanation, though rather gratuitous, is certainly coun- 

 tenanced by two striking facts : 1. The principal agents in the 



* Read before the Literary and Philosophical Society of Manchester, Oct. 21, 1825* 



