OSMOTIC PRESSURES OF SOME CONCENTRATED AQUEOUS SOLUTIONS. 483 
The outer gunmetal vessel (capacity about 250 cub. centims.) contains the solution 
which, when a pressure is applied to it, forces the dermatine rings against the 
bevelled faces GG, and thus causes a tight joint to be made with the porcelain tube. 
The joint between E and F is made good by another dermatine ring X, which is 
compressed between the metal ring I and the nuts JJ. 
The ends of AB are closed by pieces of thick-walled rubber tubing KK, through 
which the brass tubes LL are passed; a water-tight joint between LL and the inside 
of the porcelain tube is obtained by compressing the rubber between the metal 
washers MM and the nuts NN. # The brass tubes are joined by rubber tubing, one to 
a glass tap and the other to an open glass capillary—-the latter, which we shall call 
the water gauge, was graduated in millimetres and calibrated ; one centimetre of the 
bore contains 0'00312 cub. centim. The outer ends of E and F have threads cut on 
* It seems advisable to point out that the rubber tubing KK is unaffected by the pressure put upon the 
solution. 
3 q 2 
