180 Mr. Emmetl on the [Sept 



Article III. 



On the Mathematical Principles of Chemical Philosophy. 

 By Mr. J. B. Emmett. 



(Continued from p. 40.) 

 SIR, Hull, July. 1820. 



Attraction in General. 



By attraction is to be understood a tendency which any num- 

 ber of particles or masses of matter have, when at hberty, to 

 approach towards each other, or, as it is defined by Sir I. 

 JS^ewton, definition 5 : " Vis cenb-ipeta est, qua corpora versus 

 punctum ahquod tanquam ad centrum undique trahuntur, irapel- 

 luntur vel utcunque tendunt." We are, and most probably shall 

 ever be perfectly ignorant of the nature of that which we deno- 

 minate attraction ; there are ample proofs of the existence of 

 such a force, and though mathematical investigations lead to a 

 development of its laws of action, they can never make us 

 acquainted with its intimate nature ; I, therefore, wish it to be 

 minutely understood that the following; researches relate only to 

 the manner in which this force operates in producing the various 

 phenomena of corpuscular action. 



It is demonstrated, Princip. lib. 1, prop. 11 and 71, that every 

 particle of matter in nature attracts every other particle, the 

 force being in the inverse duplicate ratio of the distance ; its 

 actual operation in masses of terrestrial matter is experimentally 

 proved by the phenomena of the tides, by the observations of 

 Dr. Maskelyne (Phil. Trans. 1776), and in still smaller masses 

 by the experiments of Mr. Cavendish. The ascent of water in 

 capillary tubes is also a proof that the particles of water have a 

 tendency towards those of glass ; in each of these, it would 

 appear that the attraction of the whole is made up of the sum of 

 the attractions of the several particles ; and it is easily demon- 

 strable, from various chemical phenomena, that this centripetal 

 or attracting force really resides in every ultimate atom or parti- 

 cle of matter ; thus, wlien dry carbonic acid is mixed with dry 

 ammoniacal gas, there is an immediate condensation, and solid 

 matter is formed : the gaseous particles must have evidently 

 tended to each other with a very considerable degree of force, 

 since they now occupy a volume many hundred times smaller 

 than that which they previously filled, and we are totally unac- 

 quainted with any mode by which this can be effected, excepting 

 by the operation of an inherent tendency in the particles of 

 matter, when at liberty to approach each other ; and since we 

 know that such a tendency really exists, and is operative between 

 the larger masses of our system, there is nothing extravagant in 

 .supposing the above and all similar effects to result from the 

 operation of such force ; but to remove all doubts respecting it^ 



I 



