1 822.] Mathematical Principles of Chemical Philosophy, 433 



of combustible matter, and produce a fire of unlimited magnitude. 

 If this be the result of any motion, the whole must have been 

 communicated from the single grain of sand, for from the union 

 of the particles of the combustible body with those of oxygen, 

 no such motion can possibly result ; and every person vs^ho is at 

 all acquainted with but the firstprinciplesof mechanics must see 

 that such an effect is utterly impossible, and absolutely opposed 

 to every known law of the communication of motion, it being 

 quite impossible that the motion given to a small mass of matter 

 can communicate a greater in greater masses, which must be the 

 case, if the cause of heat be motion. Still more impossible is 

 the existence of a mere vibratory or undulatory motion. 

 , In the above researches, perhaps, I may not have described 

 the sort of motion which is intended; the reason why I have 

 selected that of rotation is, because it is the only one which can 

 have any permanency, and has been more particularly defined 

 by some writers, than either vibration, undulation, or any other 

 that has been supposed ; and in general, the intestine motions 

 that have been introduced to explain the phenomena of heat 

 have been expressed in such vague terms, and in a manner so 

 totally destitute of precise definition, that it is impossible to 

 collect any thing that v/'iM enable any one to submit it to a 

 mathematical inquiry. I have, therefore, selected that which 

 of all others is the most likely to answer the conditions, being 

 the only one that can be permanent, when there is no resistance 

 opposed to it. 



In the next, I shall apply the principles to the constitution of 

 hquids. 



{To he continued.) 



Article X. 



On Diaspore. By G. B. Sowerby, FLS. 



(To the Editor of the Annals of Philosophy.) 

 SIR, 



A SECOND mass of this curious and rare mineral has just 

 fallen into my hands : it is a remarkable circumstance that the lo- 

 cality of a mineral so extremely singular, and at the same time so 

 •well characterized, should have remained for so long a period 

 unknown; for it will be recollected that the only mass hitherto 

 known had come accidentally into the hands of M. Lelievre, and 

 that from this specimen, whatever small bits exist in collections 

 have been broken. From the data which I have with this speci- 

 men, I think I shall be able to trace its precise locality. 



Mr. Children has been so obhging as to subject some frag- 

 ^eio Series J vol. in, 2 f 



