[CLARK] ANGLE OF CONTACT ON GLASS 53 



tends to creep between the glass and mercury, being opposed by the 

 hydrostatic pressure and perhaps by other things. 



Experiments undertaken to discover the presence of this creeping, 

 show that it exists. A large number of glass tubes were cleaned and 

 dried and sealed at one end. These were about 8 mm. in diameter and 

 10 cms. long. Some freshly distilled mercury was poured into the 

 tubes and H2SO4 solutions of different concentrations were poured on 

 top of the mercury. The tubes were put in a quiet place for observa- 

 tion. The acid solution could be seen creeping down between the 

 mercury and the glass and while there are irregularities the stronger 

 solutions creep more rapidly. 



