<)8 APPARATUS FOR THE ANALYSIS 0? GASSES. 



chemical properties of the gas, as ascertained by combtts- 



Carbomcndc] t \ 0lu [ t may b e remarked, also by comparing the two last 

 not always in . * J r ° 



proportion to columns or the second table, that the carbonic acid pro-* 

 the oxigen ex- duced does not always bear the same proportion to the oxi- 

 -** 1 e ' gen expended. Thus the first product of gas from cannel 



coal combines with 234 measures of oxigen gas; and gives 

 139*7 of carbonic acid. But the gas from coal tar, with 

 only an equal consumption of oxigen, yields 150 measures 

 of carbonic acid. 

 Coal gas not 5* The aeriform product of coal does not precisely answer 

 acilywith any to tne characters of any one of the combustible gasses, with 

 other combus- which we are acquainted. The first product, however, of 

 the distillation of ciminoa pift coal, after being washed with 

 potash, approaches very nearly in its properties to carburet- 

 ted hidrogen gas. The gasses, which surpass this in speci- 

 fic gravity, are mixtures of carburetted hidrogen with ole- 

 fiant gas, and perhaps a small proportion of carbonic oxide. 

 The lighter gasses, in addition to carburetted hidrogen,- 

 probably contain a variable proportion of hidrogen gas and 

 a small quantity of carbonic oxide. The extreme levity of 

 some of the products, especially of the gas from Merthyr 

 coal, cannot be explained on any other supposition. 

 Product. ofthe 6. The products of the combustion of a cubic foot of 

 coaUas? * 1 ° f coal S as > of medium quatoy, viz. of the specific gravity 

 622, (such as the first products from Newcastle on Tyjie 

 coal) may be stated as follows: 

 A cubic foot, at a mean of the barometer and ther- Grain;?. 



mometer 333*5 



By combustion, it yields 817'3 grains of carbonic 



acid, the carbon in which may be estimated* at* • 033.7 

 Grains of hidrogen in a cubic foot of coal gas. . . . 99*8 

 But 99*8 grains of hidrogen are equivalent to the satura- 

 tion of 554*9 grains of oxigen, with which they form 654*7 

 grains of water. Hence the oxigen consumed ought from 

 calculation to be 8 1 7*3 — 233*7 = 673-6-f 554*9= H2S 

 And the quantity actually consumed appears by 



experiment to be • • • • 11 1 0*3 



Errour 17*7 



* Assuming the carbon to be 28 6 grains in 100 grains of carbonic 

 *cid, as is satisfactorily proved by the experiments of Messrs. Allen and 

 Itlfr* The 



