194 Mr Herschel on the Mechanical Effects of 



The paper in question purports to be an extract from a 

 treatise read in 1808 to the Academy of Berlin, containing 

 his principal results, which, digested by him into aphoristical 

 propositions, (in aphoristischen Satzen,) run as follows : 



1. So soon as chemical affinities are excited in galvanic pro- 

 cesses, there takes place at the same time an increased inten- 

 sity of cohesive attraction, [Flachen-anziehung, — literally, the 

 attraction of surfaces.) 



2. That the connexion which has been supposed to exist be- 

 tween cohesion and chemical affinity receives from this a not- 

 able confirmation. 



8. That the increase of cohesive attraction arising from elec- 

 tricity, between bodies which act chemically on each other, is 

 altogether different from any electrical attraction of bodies hi- 

 therto observed. 



4. There is ground to suspect, that, in the galvanic process, 

 attractions at a sensible distance operate in conjunction with 

 that of cohesion (Flachen-anziehung.) 



5. Increased attraction of cohesion, and exalted mutual at- 

 traction of the ultimate molecules, which arise in quite deter- 

 minate polarising points, (die in ganz bestimmten polarisiren- 

 den punkten entstehen,) are the immediate physical product. 

 The chemical product is dependent thereon by the universal 

 bond which connects adhesion with chemical affinity. 



These results he considers as proved by the facts announ- 

 ced in this paper, so far as cohesive attraction is concerned. 

 As to the attraction at sensible distances, he regards it as still 

 problematical. 



Professor Ermans results, thus aphoristically stated, espe- 

 cially the 5th, possess certainly in perfection one distinguish- 

 ing quality of aphorisms — obscurity ; but, putting the best in- 

 terpretation on them they will bear, it is still difficult to ima- 

 gine what connexion they can possibly have with the pheno- 

 mena described by me. But this difficulty is cleared up on 

 reading farther, when it appears that these general deductions 

 are totally unsupported by the facts described. The pheno- 

 mena themselves, however, disencumbered of the aphorisms, 

 are interesting and important, and are, indeed, as Jar as they 

 go, the same with some of those detailed in my paper, or im- 



