Dr. Whe well's Additional Remarks on Glacier Theories. 217 



in solution of cyanide of potassium had lost 2 grs., and re- 

 quired twelve days to lose 32 grs. ; the copper was compara- 

 tively quicker in being dissolved. 



The same tendency in the positive electrode to dissolve was 

 exhibited with the hydrochloric acid, increasing according to 

 the strength of the acid. It was also manifest in all the chlo- 

 rides; indeed every electrolyte tried indicated this tendency 

 to a certain extent; the metals used as electrolytes were pure. 

 Whether this increased tendency in the metals to dissolve, 

 when made the positive electrode, be an exalted affinity ex- 

 cited between the metal and the negative element of the elec- 

 trolyte, we will not as yet venture to assert, although the 

 facts bear evidence to this; and if so, we think it favours the 

 argument, that chemical action is the result of electricity, 

 rather than electricity being the result of chemical action. 

 But there being many phaenomena in the practice of electro- 

 metallurgy favourable to this view, I will leave the further no- 

 tice of this subject till opportunity enables me to bring these 

 facts under your notice. 



XXX. Additio7ial Remarks on Glacier Theories. 

 By Dr. Whewell. 



To Richard Taylor^ Esq. 

 Dear Sir, 



I WISH to add a few remarks to those I made on glaciers 

 in the Philosophical Magazine last month. I then pointed 

 out the differences which would exist in the condition of a 

 glacier, according as it was solid and flexible, or plastic. I 

 remarked that plastic or viscous substances are those in which 

 the particles can, when urged by suitable forces, overcome 

 their first attachment, slide past each other, and attach them- 

 selves to new particles. Of course this process occupies time; 

 and in a plastic moving mass, the motion of the parts will be 

 slower as the forces of attachment are greater, compared with 

 the forces which produce motion ; that is, as the mass is less 

 plastic or more viscous. I now wish to point out the steps by 

 which, in hypothesis, the transition might be made from a 

 solid to a plastic glacier; the latter being, as I before showed,- 

 the hypothesis which gives results agreeing with the facts of 

 glaciers. 



Supposing a glacier theorist to begin by supposing a glacier 

 to be solid (as opposed to plastic), with or without flexibility. As 

 a glacier evidently is not a simple mass sliding down an inclined 

 plane with an accelerated motion, he would have to consider 

 the force exerted by one part of the mass upon the others. 



Phil. Mag. S. 3. Vol. 26. No. 172. March 1845. Q 



