160 
adapted to the size of the bulb. A cut showing the bottle 
and finger pump is given. 
For very bad air smaller bulbs were shewn, such as were 
recommended for workshops, mines, &c. ; a convenient size 
for common life is here given : — 
No. of Strokes of 
the Finger Pump, 
or No. of Ballfulls 
of Air. 
Per cent, of Carbonic 
Acid indicated in 
the Air. 
Actual Amount of 
Carbonic Acid in the 
Air of the Ball. 
1 
60 
Grammes. 
0'2515 
2 
30 
01257 
3 
20 
0 0838 
4 
1-5 
0-0629 
5 
1-2 
0.0503 
6 
10 
0-0419 
7 
0.8 
00359 
8 
075 
00316 
9 
066 
0 0279 
10 
0056 
00251 
11 
0054 
00229 
12 
0 0499 
00209 
13 
0-0460 
00193 
14 
00428 
00180 
15 
00399 
00167 
