404 
DR. F. P. BURT AND DR. E. C. EDGAR ON 
being immersed in a water-bath so that the temperature of the mercury could be 
recorded satisfactorily. This mercury was run out and weighed. A mark was next 
made on the capillary just above the dead-space; mercury was introduced again to 
the level of the mark, and this quantity was run out and weighed. 
Weight of mercury from dead-space 
point to end of stop-cock. 
Temperature. 
Volume. 
g r - 
°C. 
c.c. " 
(1) 192-14 
21-5 
14-188 
(2) 192-17 
20-5 
14-188 
(3) 192-20 
20-0 
14-189 
Mean . 
14-188 
Weight of mercury from mark on 
capillary to end of stop-cock. 
gr- 
(1) 205-76 
21-5 
15-194 
(2) 205-84 
19-0 
15-193 
(3) 205-90 
18-0 
15*195 
• 
Mean 
15*194 
Therefore volume of dead-space = 15-194-14-188 
= 1 -006 c.c. 
The pipette was now filled with mercury up to, but not including, the bore of the 
tap, C, and cooled to 0° C. with melting ice. Mercury was then run out from the tap 
to the mark on the capillary, care being taken that the initial and final temperatures 
of the warm mercury in the dead-space and tubing below it were the same. 
Weight of mercury from 3-\vay tap 
to mark on capillary. 
Temperature. 
Volume. 
g r - 
° C. 
c.c. 
(1) 4160-03 
0 
305•986 
(2) 4160-09 
0 
305•990 
Mean . . 
305-988 
Total volume of pipette 
= 305 • 988 + 1 • 006 = 306 • 994 c.c. 
