( 439 ) 
connection with this the ground-glass stopper of the pycnometer was 
made very long. Our apparatus had a capacity of ± 22 cc.; it was 
gauged by means of water carefully freed from gases by boiling. 
The weighings. were carried out on a balance, on which ~ mg. 
could be read. All weighings were reduced to vacuum and to 
the density of water at 4°.0. 
After the substance which was to be examined, had been introduced 
into the pycnometer, the latter was filled with toluene, and 
connected with the air pump. When the toluene had boiled for some 
time, the pycnometer was again filled up with thatliquid, and placed in a 
thermostat, which was kept at 18°.0. The thermometers used were 
tested by a normal thermometer (divided into which had been 
tested by the Physikalisch-Teehnische Reichsanstalt at Charlottenburg. 
The stopper of the pycnometer had a capillary bore; the upper 
surface of the capillary was made opaque by grinding. As soon 
as this upper surface remained perfectly dry for ten minutes, the 
liquid was sucked off by means of a capillary pipette down to a mark 
on the capillary of the pycnometer. Then the pycnometer was 
removed from the thermostat, and weighed after having been carefully 
dried. All the determinations were made twice. 
For the toluene used we found: d —- — 0,8666. 
4°.0 
Table I contains the results of the determinations at 18°.0. 
TABLE 1 *) 
Temperature 18°. 0. 
Name j 
tance 
Weight | 
j ^ gr. j 
Weight 
of the 
expelled 
toluene in gr. 
! Weight 
of the 
1 expelled 
water in gr. 
1 
18°.0 
49.0 1 
Remarks 
Diamond 
! 9.9790* 
2.8296* 
3.514 
Graphite 
8.4424* 
3.2964* 
2.217 
Graphite 
8.5504* 
3.3412* 
_ 
2.215 
White tin 
16.8488 
_ 
2.3082 
7.281 
prepar. from grey tin 
White tin 
23.7052* 
3.2458* 
7.285 
„ from melted tin 
Grey tin 
33.4100* 
_ 
5.7953* 
5.751 
fine powder 
Grey tin 
29.9170 
- 
5.1789 
5.763 
coarser „ 
) The values in this table marked with an * have served in the further 
