522 O/i Magnetism, Cohesion, Adhesion and Viscosity. 



doubt that it is owinrr mainly to the gelatine they contain, that 

 these needles show such a remarkable degree of attraction for 

 nearly all bodies. 



I do not mean to say that all cohesion is jnirely magnetical 

 in the extended sense I have given to the term, lor such an 

 opinion is scarcely reconcilable with what is observed in che- 

 mical combinations, where we see elements clianging places 

 according to what is called elective affinity. In the various 

 theories that have been put forth to account for chemical com- 

 binations and the cohesion of bodies, the attractions antl re- 

 pulsions of different electrical states have been proposed by 

 the celebrated Berzelius; but though this might, as a theory, 

 obtain currency amongst scientific men, and enable them to 

 reason with facility, as long as acids and their bases are con- 

 sidered, yet it is clearly in fault the moment it is applied to 

 explain the cohesion of simple bodies, such as the pure metals. 

 - Many instances may be observed in the preceding experi- 

 ments, that favour the notion of the existence of elective 

 affinity between the various bodies that have been exj)eri- 

 mented upon, but to which immediate electric agency can with 

 difficulty be conceded; and we must therefore have recourse 

 in such cases to what are called the laivs of nature for their 

 explanation. With regard however to the combinations of 

 acids and alkalies, I believe the varying preferences they ex- 

 hibit when brought near one another to result fiom electricity, 

 though magnetism is not without its share in effijcting tiieir 

 union; and I hope shortly to be able to present some con- 

 siderations tiiat will render this opinion highly probable, by 

 making known a discovery I have made of the antagonism of 

 heat and electricity, as well as the proofs of a single electric 

 fluid. 



I cannot take leave of this subject without expressing my 

 unfeigned admiration for the skill exhibited by Dr. Faraday, 

 in his experiments on the same subject, as well as on so many 

 other occasions ; and if we differ in our views of magnetical 

 phaenomena, it will be easily accounted for, by the opposite 

 results we have obtained, owing to our methods of experi- 

 menting, and the greater range and variety of observations 

 that the present one has given birth to, over those recorded 

 by that eminent experimenter. 



I hope that the state of my health, which has compelled 

 me to dictate this communication, and which has prevented 

 me from giving it the benefit of after-perusal, will be accepted 

 as a sufficient excuse for any oversights that may be observed. 



Paris, ]5, Rue de Tournon, 

 19th May, 1847. 



