ME. W. CEOOKES ON THE ATOMIC WEIGHT OE THALLIUM. 
90 9 
The weight of air displaced &c. is taken separately for each weight in all cases, but 
is omitted in subsequent examples (the sum being given), to prevent the introduction 
of useless figures. 
WEIGHING OF GLASS APPARATUS + NITRATE OF THALLIUM IN RARE ATMOSPHERE. 
Vacum-balance. 
Exhausted. Left pan removed. 
Platinum weights. 
Weights. 
799-3600 
Pan = 206-3733 
1005-7333 
True value in air. 
799-346792 
206-379646 
1005-726438 
Weight of air 
displaced. 
0-047117 
0-012040 
0-059157 
Volume in water 
at max. density. 
38-423 
9-824 
48-247 
Therm. =69°-5 F. =21° C. 
Barom. = 29-775 in. = 756-27 millims. at 0° C. 
Gauge =25-141 in. = 638 - 57 millims. at 0° C. 
756-27 
638-57 
117-70 millims. pressure. 
Weight of left scale-pan of air-balance, which was removed to relieve the beam in 
weighing the heavier pieces of apparatus : — 
Weight of air Volume in water 
Weight. True value in air. displaced. at max. density. 
179-7365 179-719377 0-010429 8-513 
Weight of left scale-pan of vacuum-balance taken in air-balance : — 
Weight of air Volume in water 
Weight. True value in air. displaced. at max. density. 
206-3733 206-3719646 0-012040 9-824 
Weight of air displaced by scale-pan =0-02403 gr. 
Volume in water of maximum density =24*244 grs. 
CALCULATION OF VACUUM-WEIGHT OF GLASS APPARATUS + NITRATE OF THALLIUM FROM 
GIVEN DATA. 
By Table A, 
First Weighing in Air of Ordinary Density. 
lo 
0-00129381 1 
5 1 + 0 - 03656 * ‘ 780 
for 22°-7 C. 
1 22° is 4-197488-10 
f 7 is 1027 
4-198515-10 
