482 Mr. J. B. Hannay. [June 10, 



larity disappeared. This again shows that pressure has little or no 

 effect upon the cohesion of a liquid, and that it is reduced to zero at 

 about the same temperature notwithstanding the pressure. 



It would appear, then, that the boiling line does not extend beyond 

 the critical point, but that the critical point lies upon an isothermal, 

 which is the limit of the liquid state. 



I have examined several liquids and liquefied gases, including 

 C0 2 , NH 3 , S0 2 , N a O, CS 2 , 001 4 , CI, CH 4 0, C 2 H 10 O, and C 2 H 6 0, and I 

 find that the capillarity disappears at or near the critical point, and 

 pressure does not cause it to reappear. 



I have also measured the rate of decrease of capillarity with tempe- 

 rature, but have not yet had time to reduce the arbitrary readings to 

 actual measurements to find whether or not any systematic relation 

 exists. I shall bring this work forward at some future time. 



I have still another method of examination to bring before the 

 Society. An apparatus was arranged with the tube for experimenting 

 with the liquid bent at an obtuse angle, as shown in the sketch. 

 The liquid was contained in the upper part, A, inclosed by the mer- 

 cury, B ; while the lower part, C, inclosed in the apparatus, was filled 

 with nitrogen or other permanent gas. On applying pressure the 

 nitrogen is compressed into small space, and by gently tapping the 



