Electrolytic Crystallization of Metals. 33 



In line (2), we have now, however, the a particles turned 

 towards the negative pole N^ and the h particles towards the 

 positive. We therefore assume that the molecules rotate on 

 their axes and form up as in (3), ready for a second electrolytic 

 effect represented in (4), where we see that two particles, /a;^, «^, 

 of the anion have now been set free at the positive pole, and two 

 particles, 3*, 3®, of the cation at the negative pole, leaving the 

 remainder of the substance in the same compound form as at 

 first. A continued repetition of these processes may be supposed 

 to constitute electrolysis of a simple binary compound in the 

 liquid state. In the case of solutions where there are present 

 two compounds (the solvent and the substance dissolved in it, 

 only one of which may be undergoing electrolysis), the action is 

 evidently more complex. Still a similar process seems possible. 

 It must not of course be understood that the above is put forward 

 as anything more than a working hypothesis. There is no 

 experimentum cruets to prove it, but it appears to me to avoid 

 some of the difficulties inseparable from the dissociation theory 

 to which I have referred. 



Mr. Workman — There was one point which struck me if I 

 followed Mr. Brown correctly. The atoms of tin were free 

 atoms, as far as the explanation went, and the red dots shown 

 on the screen represented free atoms. Were the other atoms 

 also free ? The experiment was exceedingly beautiful, and well 

 worthy the lecturer. 



Mr. Brown — I do not quite understand Mr. Workman's 

 difficulty. In the beginning, when the substances are all 

 combined, there are according to the view I adopt no free atoms. 

 What I meant by a " free atom " was an atom wandering about 

 by itself as required by the dissociation theory. In reply to the 

 question asked as to what cells I have used for my experiments^ 

 I may say that I am using five dry cells. I do not use all the 

 cells for every experiment ; for instance, that with tin chloride 

 only required three. I have an arrangement for putting in 

 circuit any number of cells I require. 



