^0 MR. HENRY ON COMBUSTIBLE 6ASLS. 



In order to afcertain how much oF the diminution was owfiig 

 to the condenfalion of olefiant gas, the proportion of oxygen- 

 ized acid, required for the faturation of that gas, was care- 

 fully afcertained. After feveral trials, it was found that 3 m. of 

 the oxygenized acid with 2| pure olefiant gas, prepared accord- 

 ing to the Dutch chemifts, left only 0.15 m. of cpmmon air 

 derived from the veffels. It appears, therefore, that the gas 

 irom oil and from tallow contains about 1, and that from wax 

 I olefiant gas, the refi being pure hydro-carburet. 

 Hence it isfeen The refults of thefe experiments, in connection with a fa6l 

 why vvaihingdi- communicated to me by Mr. Dalton, explain fome circum- 

 ^oduft of car- ^^nces obferved by Mr. Cruickftiank, for which that ingenious 

 bonic acid af- chcmift was at a lofs to accQunt, viz. the great variation in 

 (n'^an h^ydm-"' the produds of carbonic acid, obtained by burning the fame 

 carburet. For hydrocarburqt vyben wafhed and when unwaflied, or when 

 "lefi'^T ''aT^ '^^^ ^^"^ kept in contad with water; though the gas, when ori- 

 ginally procured, was perfectly free from carbonic acid. The 

 plefiant gas, Mr. Dalton has afcertained, is far more abforb- 

 able by water than other fpecies of hydrocarburet, viz. in the 

 proportion nearly of f. Now the gas from camphor, I find 

 to contain much olefiant gas, and indeed this might have been 

 inferred from Mr. Cruicklliank^s ovvn ftatement, who obferves 

 that this gas, by admixture with oxygenized muriatic acid, 

 undergoes a confiderable diminution of bulk. The pure hydro- 

 carburet, on the contrary, I have never feen at all condenfed 

 by conta6l with this gas, in the rapid manner obfervable in 

 olefiant gas or mixtures containing it; though, by confinement 

 together for forpe hours, they are mutually decompofed into 

 Jlydiocnrburcts common muriatic acid, carbonic acid, and winter. The hydro- 



trom ether and carburets ffom ether and alcohol alfo contain olefiant gas; and 

 alcohol alfo con- ' . ' ... , , „ . ^ ' 



tain ol. gasj this, I apprehend, will be found to be the fact with all infiam- 



wh.ch IS the mable gates, which by combuftion give more than their own 



the difFercnce in ^^^'1^ of carbonic acid. The variable produ6is of carbonic 



carb. acid pro- acid, obtained in Mr. CruikQiank's experiments, from equal 



Cruikfhank.' quantities of different Jiydrocarburets, cannot, therefore, be 



confidered as denoting lb many diltin6t fpecies of carburetted 



hydrogen; but as owing to the admixture with this of various 



proportions of olefiant gas. 



Error of that |t will not, I am perfuaded, be regarded as indicating a 



author refpeft- vyifli to dctra61, in the finalleft degree, from the credit due to 



tFffn of car"bu'!"' ^''* ^*'"^^^**"^' whofp mcmoirs on the hydrocarburets and 



retted hydrogen . . Carbonic 



ga/ea. *.•■..!. 



