MR. HENRY ON COMBUSTIBLE GASES. ^1 



<carbonic oxide I eftimate among the moft ingenious, and ge- 

 nerally ("peaking, the moft fati.sf'a6lory examples of chemical 

 refearch, if I obf^rve that the part of his table (vol. V. p. 8 

 of the 4to feries of this Journal) which relates to the conftitu- 

 tion of the carburetted hydrogen gafes, I confider as entirely 

 erroneous. To excit: firong fulpicion of the accuracy ot the 

 proportions afligned to thefe gafes, it is furely fufficient that 

 one of them (the gas from moid charcoal) is ftated to contain 

 m 100 cub. in. zr 1 4| grains, no lefs than 9 grains of water, a 

 proportion abfolutely inconceivable; and the fame obje61ioii 

 applies, in a Ids degree, to the other cafes. Now in 100 

 cubic inches of the muriatic acid gas, 1 found the abfolute 

 quantity of combined water to be only 1.4 gr. (Phil. Tranf. 

 iSOO) ; and it is rendered highly probable, by the experiments 

 of Clement and Deforme f/iw/?. de Chim. XLTI. 121) that all 

 gafes contain the fame quantity of water. In the inf^aiice of 

 the gas from charcoal^ Mr. C. was mofi: probably mifled, by 

 not having fufpe6ted the prefence of the carbonic oxide; and 

 the corredion is to be made as follows. One hundred cubic 

 inches ( = 14| grains-) combined with the proper quantity of 

 oxigen, gave \d grains of carbonic acid., containing very 

 nearly 4 grains ef carbon ; and fuppofing the carbon in the gas 

 before cembufBon to have been in the ftate of carbonic oxide, 

 it wodd be combined with about 9 grains of oxygen, and 

 would conftitute 13 gr. or 43| cub. in. of carbonic oxide, — 

 There remains then only i\ grain, of the 14|- fubmitted to* 

 experiment to be accounted for, which is very exadly made 

 up by the refiduary 51\ cub. in. of hydrogen gas, taking the 

 weight of KTO cub. in. of hidrogen to be 2.6 gr. The water 

 contained in the gas may, I think, be fet out of thequeftion ; 

 for it mu-ft be recolleded that the produft of the combuftion is 

 in part aeriform; and it may be confidered as a tolerable ap- 

 proximatimi to the truth, that the gas from charcoal contains, 

 in 100 inches, 43 of carbonic oxide, tbe remainder being 

 principally hydrogen gas. 

 • With refped to the prefence of hydrogen in the carbonic Carbonic oxide 



oxide, whicli has been a topic of controveriy, neither the faa*^"" "°^"?f '" 

 . . . „ . . . combined hidro- 



nor the negative can, I think, be at prefent with certainty af-gen, &c. 



£rmed. If however any hydrogen be contained in it, I fliould 

 <Ieem it an accidental and not an elTential ingredient, and am 

 of ojpi.nion that, if prefent at all, it exifts in the ftate of hydro- 

 gen 



