400 Experiments on the Gas from Coal. 
I shall only state the general results, and I 
shall describe, in a subsequent part of the 
paper, the methods of analysis, in order 
that other persons, who may choose to com- 
pare my experiments with their own, may 
conduct them under equal circumstances. 
By the expression impure gas, is to be un- 
derstood, the gas precisely in the state in 
which it was collected from the retort; and 
by purified gas, the same product after being 
freed from carbonic acid and sulphuretted hy- 
drogen by solution of pure potash, applied 
in very small quantity, relatively to the vo- 
lume of the gas, and with the least lenge 
adequate to the effect. 
TABLE I. 
Shewing the Quality of Gas from 11201. of Cannel, 
at different periods of the Distillation. 
Hours from the 100measuresof im-|(100 m. purified gas||100 m.of pu- 
commence- pure gascontain of consist of rified gas. 
ment. —_— || -  ]] cons. give” 
Sul, hyd,  carb.ac.|/Olef. otherinfl. az. || oxyg. carb, ° 
gases acid. 
< an hour...{( 0% 5E 16 | 64 | 20 || 180] 94 
1 hour.......|| 3 $ 18 | 774} 42 || 210) 112 
3 hours......|| 22 Qt 15 | 80] 5 200; 108° 
5 hourS.cec0o|| BFE 2% 13.| 72 | 15 |) 176} . 94 
7 hours...... 2 2 19 | 76115]! 170) 83 
9 hours......|| OF 2 8 | 77 | 15] 150) 73 
10% hours....e.|| 0 2 6 | 74] 20 {| 120, 54 
12 hours......|| 0 Of |} 4 | 764 20]| 82/° 36 
