122 



Experiments on the Gas from Coal. 



TABLE II. 



Showing the Quality of the really combustible Part of the Gas, 

 at (liferent Periods of Distillation. 



Take oxygen. Give carb. acid. 



100 measures of 

 half hour's gas 

 1 hour's gas 



3 



5 



7 



9 



lOf 



12 



The next set of experiments was made on gas from common 

 coal, got atClifton near Manchester, and of fair average quality. 



TABLE III. 



Showing the Quality of the Gas from \\20 lbs. of common 

 Coal, at different Periods of the Distillation. 



Exclusive of the azote, with which the three last portions of 

 gas were mingled, they consumed oxygen and gave carbonic acid 

 as follows. The seven hours gas in this instance, as sometimes 

 happens from irregularities of temperature, was more combustible 

 than that collected two hours sooner. 



Consumed oxygen. Gave carb. acid. 

 100 m. of 7 hours gas . . 140 . . . . 75 

 9 hours .. .. 123 .. .. 66 

 11 hours .. .. 106 .. .. 50 

 A comparison of the results exhibited in the third table, with 

 those of the distillation of cannel coal, is greatly in favour of the 

 latter substance as a source of light. This will appear most di- 

 stinctly, by setting against each other the ])roportions of oxygen, 

 which are consumed by the gases evolved from the two substances 

 at equal times from the commencement. 



TABLE 



