66 Db. Macvicae's Adaptation of the Philosophy of 



an effective apparatus, which shall be constant, therefore, not only must 

 c be kept clean or clear of H, but also of z. — (Daniell.) 



(c.) It is also to be considered, that while the assimilative influence 

 of the action at Z represented by H O tends to assimilate all the cor- 

 responding lines of a 5 between Z and C, by transforming them into 

 HO, the assimilative influence of the unchanged attends to reassimilate 

 that which has been transformed into H O, and to effect its relapse into 

 aq. The mass of water between must therefore act as a resistance to 

 the formation and progress of the current. Another condition, there- 

 fore, to the successful establishment and maintenance of such a current, 

 must be to diminish, as far as possible, the breadth of aq between z 

 and c, the resistance being proportional to this breadth. 



Feictiokal Electeicitt. 



7. It follows from our views, however, that cuiTcnts may be developed 

 otherwise than by molecular transformation or chemical change. There 

 is, in fact, in every body, a great amount of undulating action awoke 

 and sustained by the specific heat of its constituent molecules. On the 

 simple application, therefore, of two dissimilar masses to each other, 

 under the law of assimilation, traces of a current may be established ; 

 and when that application is rendered forcible, as by heat, pressure, or 

 friction, it may be expected that that current shall often become palpable 

 to the senses. Thus, let F (see a fig. of Electrophorus), represent a 

 stratum of fur, and E a stratum of resin, and let them be rubbed 

 together, the systems of undulations representing each, actuating each, 

 and existing in each in a chaotic state, will, under the law of assimilation, 

 tend to pass upon the other, thus so far assimilating the other to itself. 

 The previously existing systems of undulation in both, will therefore be 

 no longer merely chaotic in either. From the first moment of presenta- 

 tion, pressure or friction, each will begin to act in a manner normal to 

 the surfaces of contact ; and supposing this action to have penetrated 

 both, the remote surface of the fur will be actuated by the system proper 

 to the resin, and the remote surface of the resin by that proper to the 

 fur, while at the region of union common to both, both will symmetri- 

 cally interpenetrate perpendicularly to the common surface of the fur, 

 and resin. Let then the fur and the resin be separated, the surface of 

 the fur just taken from contact, will now manifest sti'ongly the system 

 previously tending to pass upon the resin, that is, the system proper to 

 itself, while the corresponding surface of the resin in like manner will 

 manifest that proper to itself; and by applying conductors in various 

 ways, at various moments, so as to relieve the tension, and constitute cur- 

 rents which, without conductors, immediately stop, a variety of interest- 



