on CBEMICXL APPIMITT.' |7 



ter*. ■ Tbe irnportaot effect* that »uch a pnncipl<», if 



adopted, would have on our chemical and physical reasoning, 



<;crtaialy require, that it ahould be established by the most -s 



•tttisfactory evidence. How far it is ho will appear from the • 



following ob<erfation» and experiment*. ^ 



Gravitation and cheuiictl union are operations apparently Connexion wf 

 dlssimiluri and it is by no means surprising, that ^hey ^^-^jj^'l^^^j]^^'* 

 should have been, for a considerable time, referred to the tion, 

 agency of diiferent powert. At present we cannot but per- 

 ceive, that gravitation is intimately connected with chemi-* 

 cal action, by the various intermediate effects of the at- * 

 traction of cohesion, of capillary attraction, and of hygro- 

 Bietiic affinity. It has never, indeed, been demonstrated, 

 that clieinieiil affinity it identical with the attraction of gra- 

 svitation; nor do I consider the opinion as admitting of such 

 proof. Philosophy has in this instance done enough, and 

 perhaps its utmost, in removing all objections to a general 

 doctrine, which is reoommended by strong and insuperable 

 analogies. Now those who admit, that gravitation and che- 

 Hiicat aOiiiity depend on the same principle, cannot for a 

 moment maintain, that chemical attraction and electrical which Is not 



attraction are identical : for it can be demoostratcd, that tlte ^^"^ ^^"^^ ^"^ 



electrical air 



attraction of gravitation is not identical with electrical at» tiactiun, 



tractioB. 



In the first place, if gravitation depend on difference of for bodies in 



electrical state, there must be some body at the centre of **'.^^f^"\*^^^ 

 . . t n cal states d» 



the Earth having an electncol state different from that of not gravitate 



every body at the surface, since every body at the surface tl»ff«^f*^'«ly ^» 



. II o li • 1- thecentrei 



tt apparently attracted to the centre, nut as all bodies at 



the surface are su{)posed to have different electrical states, 

 in respect to one another, there cannot exist the same dt^ 

 gree of difference between tlie electrical state of any two 

 diititimilar bodies, and that of the body at the centre, and 

 consequently dissimilar bodies should be attracted to the 

 ceutre with unequal d«*gree« of force : a conclusion per- 

 fectly inconsistent with ihe principle* established by Sir 

 Isaac Newtocf^s beautiful experiments with th« pendu- 



» PbiUs. Tran^ 1807, p 29: at Jjur. toI. XIX, p. 50. 

 V«i.. XXIX-.May» Uil. g lum, 



