1881.] Dr. G. Gore. Phenomena of Capillary Electroscope. 295 



molecules, the 42 molecules of bromide and chloride are still expand- 

 ing. Finally, from 133° C. to the fusing point, all the molecules are 

 expanding, 42 of them quickly and 58 slowly. And during this heating 

 from 0° C. to 133° C, a highly crystalline brittle solid has been con- 

 verted, within the mass of two crystalline solids, into a plastic amor- 

 phous body. 



VI. "Phenomena of the Capillary Electroscope." By G. GORE, 

 LL.D., F.R.S. Received November 23, 1880. 



(Abstract.) 



In this communication is described an investigation of various of 

 the conditions of the above phenomena. The phenomena have been 

 found to be purely physical except in those cases where the electricity 

 was of too high tension and produced electrolysis, and in those in 

 which the solution acted chemically upon the mercury. 



The influence of the kind and strength of numerous solutions was 

 examined, including those of various salts of neutral, alkaline, and 

 acid reaction, and of various acids, and the results are described. Of 

 the salts, some gave anomalous results ; alkaline cyanides, for instance, 

 reversed the direction of the movements of the mercury. Inferior 

 conducting liquids, such as aqueous ammonia, gave feeble movements. 

 Good conducting solutions, such as neutral salts of the alkalies, 

 potassic cyanide, and dilute sulphuric and phosphoric acids, yielded 

 strong movements. Both the kind and the degree of dilution of the 

 various substances had great influence upon the results. 



By examining the question of the influence of the relative dimen- 

 sions of the mercurial surfaces it was found that no such influence 

 existed, simply because one surface of liquid metal with a suitable 

 solution was alone sufficient. 



Attempts were made, but without success, to obtain the same 

 movements of two aqueous solutions instead of mercury and a watery 

 liquid. Other effects, of apparent movement, &c. (described in a 

 separate communication, see " Influence of Voltaic Currents on the 

 Diffusion of Liquids," {ante, p. 250), were obtained. 



The question as to whether the movements were wholly due to 

 alteration of volume of the mercury was also investigated, and the 

 conclusion arrived at was, that while a very minute alteration of 

 volume did occur, nearly the whole of the movement was due to other 

 causes. 



The influence of adhesion was freely examined, and the hypothesis 

 proposed that the motion is primarily due to a direct mechanical action 

 at the immediate surfaces of contact of the mercury and solution, 



vol. xxxi. z 



