UNIVEESITY COLLEGE, LONDON 119 



electrically, for they are attracted or repelled, according 

 to their nature, from one or other of the electrodes con- 

 verging a current into the liquid in which the particles 

 are suspended. During the twenty-five years which 

 have elapsed since 1892 much has been done by various 

 observers and especially by Professor Jean Perrin of 

 the Sorbonne. and it is now pretty generally the custom 

 to attribute these movements to the motion of the 

 molecules of the liquid in which the particles are sus- 

 pended. In 1 882 Ramsay, in considering this hypothesis, 

 appeared to think that single molecules could have no 

 effect on masses so many million times larger than them- 

 selves, as the moving particles are, and that to produce 

 an effect many molecules must coalesce and move as a 

 whole. In 1892 he seems to have retained practically 

 the same view and supposed that the effect of adding 

 an electrolyte to a liquid in stopping pedesis is due to 

 the breaking up of these molecular aggregates by the 

 presence of ions. 



From the first, on coming to London, Kamsay busied 

 himself with the idea of a Teaching University for 

 London, and to his exertions some of the changes 

 which were afterwards introduced into the method 

 of conducting the examinations of the Univer- 

 sity, so as to give the teachers a larger share in 

 determining the places of the candidates, were doubt- 

 less in part due. On June 8th and 9th, 1892, two 

 articles from his pen were printed in The Times 

 under the heading " Universities Abroad," and from 



