MR. HENRY ON COMBU.STI IJLfi GASE^i ' ^^ 



the Ihird column from the correfpondlng one in the fecohd, meafure of hy- 



what proportion of the con fumed oxigen has been allotted to "^""^P" °'^'S'"*''y 



the faturalion of the hydrogen of each hydro-carburet. Thus, 



for example, in the combuftion of the gas from coal, 70 parts 



of oxigeri have difdppeared, befides that which has entered 



into the carbonic acid ; and, lince each meafure of oxigen 



faturates two of hydrogen gas, the gas from coal muft contain, 



in 100 meafures,' a quantity of hydrogen which, expanded to 



its ufual elafticity, would occupy 140 meafuVes. By a limilaf 



mode of eflimation, the quantity of hydrogen in Other fpecles / 



of inflammable gas may be afcertained ; viz. by filbtrafting 



the number in the third from the correfponding one in the 



fecond column, in each inftance, and doubling the remainder. 



The above experiments fufficiently explain why the gas Thefe fadis ex- 

 from coal evolves fo much more light, durinor combuftion, S^'".'^^^''^^^*^^ 



o ' b * illumination 



than either hydrogen or the hydro-carburet from moid char- from the coal 



coal, becaufe, in an equal volume, it includes, in its com- V^^' '^^^, ^'^^^ 



~ . . I . I ■ c ■ n It ^s greater the 



pontion, above thrice the quantity or inflammable matter pre- more oxigen is 



fent in hydrogen gas, and nearly thrice as much as is con- '^^'1"''^^*^/°'^ '^^^ 

 tained in the gas from moift charcoal. The appreciation of 

 the degree of combuftibility of each gas, by the quantity of 

 oxigen required for its faturation, entirely agrees, as might 

 naturally be expeded, with that founded on the phenomena 

 of filent combuftion in an Argand's lamp ; for each gas feemed 

 to me to evolve light, as nearly as could be judged, in pro- 

 portion to the quantity of oxigen confumed by its detonation 

 in a clofe vetfel. Above all others, the olefiant gas * is de- 

 cidedly entitled to rank, by the fplendor and beauty of the 

 light which it yields ; and the violence of its detonation, when 

 fired with a mixture of oxigen gas, alfo furpaffes that of 

 every other inflammable gas. By exploding only .03 of a 

 cubic inch with .17 of oxigen gas, a flrong giafs tube was 



m. ; hut, after wafhing in water, was reduced to 40 02. m." In 

 this experiment one grain and \ of charcoal was confumed, and 30 

 oz. m. of carbonic acid were generated, without any change in the 

 volume of the oxigenous gas. 



* A full abftradl: of the memoir of MefTrs. Deiman, &c. on this 

 interefting gas, may be ittr^ in the 1ft Vol. of the 4to Series of this 

 Journal. Its chaiafteriftic property is that of being rapidly con- 

 denfcd into oil, by contaft with oxigenized muriatic acid gas. 



F2 " ftiatterei 



