64 Db. Macvicar's Adaptation of the P/iilosojiJii/ of 



light, give fractional numbers, and be representative of mutilated molecules, 

 not of those with which nature operates. 



Galvanic Eleotkiciti'. 



6. Where union has been abeady aecompUshed, the law of assimila- 

 tion may also be applied, so as to produce very interesting phenomena 

 in causing the molecules to retrace the steps which they have taken in 

 the course of nature ; and thus to set free a current of force at the dis- 

 posal of the chemist or engineer. 



Thus let A Q be a mass of water insulated in space, or say in a simple 

 cell of a galvanic combination. Each particle of ay is well known to 

 be resolvable into an atom of H and one of O. And let the water iu 

 one end be bounded by some substance capable of resolving it more or 

 less into H O, as for instance a plate of zinc attacked by sulphuric acid, 

 then the stratum of water adjacent to Z, or at least certain particles in 

 that stratum , will be transformed into H O. But this H O thus developed 

 will, under the law of assimilation, tend to transform into similarity 

 with itself the next particles adjacent to it towards the other side of 

 the cell, and, in fact, the whole water lying in that line. And thus 

 while at z there is a stratum of atoms of O tending to adhere to z ; at 

 the other side of the water, as for instance at the copper disc or c, there 

 will tend to be a stratum of atoms of H tending to adhere to c. But 

 this assimilative operation awoke by the action of zinc and sulphuric 

 acid upon the atoms of A Q adjacent to it, and tending to stretch 

 through the whole mass of a q lying between z and c, must be resisted 

 by the heat, and the chaotic undulating action or tension which must 

 be speedily generated in both z and o, if they as well as A q remain 

 insulated. Let z and c then be brought into contact above by a fit 

 medium, or by sloping them towards each other, so that each may rest 

 upon the other, then the state of chaotic undulatory action in each will 

 be symmetrized in both, and the action will proceed and be sustained. 

 For the undulatory action caused in z by the successive incidence of 

 particles of O upon its surface, must be assimilated to that of 0, and re- 

 presentative of O. That which is caused in c, on the other hand, by the 

 successive incidence of atoms of H, must be assimilated to that of H, and 

 representative of it. Now and H are dissimilar to each other. The 

 undulatory systems representative of both respectively, will therefore 

 be also dissimilar. When, therefore, these currents meet in opposite direc- 

 tions, they will not meet face to face with the same forms and intervals, 

 so as to resist each other and maintain a state of tension, but after merely 

 developing currents cii-culating at right angles to their direction and 

 representative at once of their mutual resistance, and of the equatorial cm*- 



