ON THE EFFECTS OF HEAT. 05^ 



fluid ; the effects of which are modified by the nature of 

 tba bodies through which it passes. The experiments and 

 observations I have made on this subject may be considered 

 a sequel to this paper, and will form the subject of a futur* 

 communication. 



Prince s Street^ Cavendish Square^ 

 Nov. 15M, 1811. 



IV. 



An Attempt to explain the Phenomena of Caloric, In m 

 Letter from a Correspondent, 



To W. NICHOLSON, Esq. 

 SIR, 



AF the following attempt to explain the phenomena at- 

 tendant on caloric will not disgrace your excellent Journal, 

 I shall feel myself much honoured by its insertion. 



It is a well-known fact, that caloric is the cause of the »i .- -^ *. 

 elasticity of gasses ; and it is equally certain, that an elec- gasses both 



trie spark, or the contact of an ignited body, will, in manv ^^"**^«^ *"'* 



' , . 1 . • , , ^ destroyed bf 



cases, destroy their elasticity, and cause them to condense caloric. 



into a nonelastic substance. These facts may be exempli- 

 fied by the decomposition and formation of water by electri- 

 city. If then, it may be asked, caloric be the cause of the 

 elasticity of gasses ; how can this elasticity be destroyed, 

 by an addition of the same substance ? 



Thirf apparent anomaly has been thus explained by j^onge^gt-K* 

 Monge. As gasses are rarefied by heat, the spark will cause planationof 

 the sudden rarefaction of that part of the mixture, throucrh '**'** 

 which it passes : this will cause as sudden a condensatioti 

 of the adjacent parts; the atoms of oxigen and hidrogen 

 will thus be made to approach each other ; they will there- 

 fore unite, and form water. 



In a volume of Experiments on acetous acid, &c., pub- Dr.Hi'iioi^ 

 lifihed by Bryan Higgins, M. D., in 1786; I find the fol- 

 lowing, and I think more satisfactory, explanation of the 

 phenomenon. 



He supposes the particles of gasses, to be surroundedwith '^^ particle* 

 distinct atmospheres of caloric; in which the densities are dfsSvS CT'' 

 reciprocally as the distances from the particles, in a dupli- calo"<^> ba? 



cate 



