X. 



Proceedings. [October 20th, 1896. 



electrolytic resistance and the increase of viscosity of such 

 a solution may afford an indication whether there is, or is not, 

 any direct connection between the two physical quantities. 

 One part of gelatine, and 5 of sodium chloride were dissolved 

 in 100 parts, by weight, of water, and the whole was kept at a 

 temperature of about 50°C. for two or three hours. The 

 solution was then cooled rapidly to about 20°C, about one 

 quarter of an hour afterwards its resistance measured by the 

 Kohlrausch apparatus was 8*5 per cent, less than a correspond- 

 ing solution free from gelatine ; since the degree of dissocia- 

 tion of the latter is over 70 per cent., it is very probable that 

 the greater part of the salt in the gelatine solution was in a 

 state of dissociation; in an hour and a half its resistance had 

 increased and was only 4 per cent, less than that of the salt 

 solution free from gelatine; its resistance then diminished, 

 and in 5^ hours was about 8 per cent, less than that of 

 the salt-free solution, after which it remained practically 

 stationary. 



Concurrent determinations by Poiseuille's method were 

 made df the viscosity, which was found to increase at a con- 

 tinually augmenting rate. In order to be sure that the liquid 

 was in the same state when used for the determination of resist- 

 ance as for that of viscosity, all the solution was mixed together 

 every hour and well stirred. Stirring doubtless affects the 

 rate of increase of the viscosity. In 8J- hours the viscosity 

 was 12 times as great as near the beginning, and was increas- 

 ing at a rapid rate ; I was then compelled to leave the work 

 for the night. By morning the solution had set into a jelly, 

 and further experiments were thereby rendered impossible. 

 Doubtless, before setting, the viscosity became very great, 

 but there was no indication of any corresponding change in 

 the electrolytic resistance, for it was practically the same as 

 the night before. 



The experiments indicate that, in the case of the particular 

 gelatine solution considered, there is probably no direct con- 

 nection between the viscosity in mass and the resistance 

 which the ions experience in their motion. 



