144 Scientific Proceedings, Royal Dublin Society. 
not consider it necessary to remove the carbonic anhydride pre- 
vious to the experiment. 
After certain intervals of time, the contents of each bottle were 
transferred to a large platinum crucible (of 115 c.c. capacity, and — 
provided with a tightly-fitting lid) and the bottle rinsed out with 
60 c.c. of the weak hydrochloric acid solution in three separate 
portions, which were also added to the contents of the platinum 
erucible. The latter was then heated on a water bath until its 
contents were dry, next transferred to an air bath heated to 150 °C., 
and after some time covered, placed in a dessicator for ten minutes 
and weighed, the heating, &c. being repeated until a constant 
weight was obtained. 
Difference in weight of residue 
Epes ||, (conditions eien ce eal 
ma From Blank A. From Blank B. 
1 Blank A. 0:0487 grm. — + 0°0008 grm. 
2 Blank B. 0:0484 =O — 0°0003 grm. — 
3 After 48 hours. | 0-0508 _,, +0:0021 ,, + 00024 ,, 
4 a Oe 0-0512 ,, +0:0025 ,, + 070028 ,, 
5 i ae 0-0537—,, +0-0050 ,, +0:0053 ,, 
6 Suto gieeane 0:0549_—,, + 0:0062 ,, +0-:0065 ,, 
ie te OS mea 0:0585 =, +0:0098 ,, +0-0101 ,, 
These results prove a very decided action, increasing on the 
whole with the time of exposure. They bear out and amplify our 
previous work on the subject. 
We did not expect to find that the duplicate experiments would 
show exactly the same results, as the extent of the action probably 
depends upon variable conditions, such as the amount of the car- 
bonie anhydride in the air of the bottle, the temperature of the 
room, the extent to which the bottle was agitated so as to expose 
fresh surfaces of glass, &c., and the duplicate experiments were 
not performed at the same time. 
1 This result is possibly too high, as we noticed during the evaporation a speck of 
some foreign substance in the otherwise clear liquid. 
