286 Description of an Apparatus for the 



An example of the analysis of a highly combustible species 

 of elastic fluid is furnished by the following experiments on 

 the defiant gas, obtained from alcohol and sulphuric acid. 

 Of this gas 100 cubic inches, at a mean of the barometer and 

 thermometer, were equal to 30 troy grains j hence its specific 

 gravity was 967. 



In the receiver oo, were contained of this gas 6*3 cub. in. 



Residue - - - - 2 



Gas consumed - - - - 4*3 



In the receiver /-, were 43*4 inches of oxygen gas. After 

 the combustion, there remained 38*2 cubic inches of mixed 

 gases, of which 8*6 were carbonic acid. None of the in- 

 flammable gas, which passed through the bent tube, had 

 escaped being burned ; for the quantity of gas in b, not ab- 

 sorbable by sulphuret of lime, so far from having been in- 

 creased, was found to have sustained a trifling diminu- 

 tion. The oxygen gas, which was consumed, amounted 

 to 13*8 cubic inches. Reducing these results to centesi- 

 mal proportion, 100 cubic inches of this gas would give 200 

 of carbonic acid, and absorb 325 of oxygen gas. This ex- 

 periment agrees with Mr. Dalton's, as to the proportion of 

 carbonic acid from the combustion of olefiant gas, but 

 assigns a larger consumption of oxvgen. It mav be ob- 

 served, however, that the specific gravity of the gas, which 

 I employed, exceeded a little the statement of the Dutch 

 chemists, who found its specific gravity to be 909, common 

 air being 1000. 



Having satisfied myself, by repeated experiments, of the 

 accuracy of the results which may be thus obtained, I pro- 

 ceeded to the combustion of the gases from a variety of ve- 

 getable substances, and especially from those which it seem- 

 ed probable might become ceconomical sources of light. In 

 the present memoir, I shall describe those only, which were 

 made on coal and a few similar substances, reserving the 

 rest for a future communication. 



Gas from Camiel Coal. 

 This was received in two separate portions. Of the first 



pro- 



