Analysis of the compound inflammable Gases. 293 



may always be expected. A part of the deficiency in the 

 oxygen actually consumed may be ascribed, also, to a small 

 portion of the inflammable gas being already in the state of 

 carbonic oxide. 



Without repeating the particulars of a similar calculation 

 made on gas of inferior quality, I shall annex a comparative 

 statement of the specific gravities and composition of the good 

 and inferior gases. . - 



Source of the gas. 



Weight 



of a cubit 



foot. 



A cubic foot 

 consists of 

 carb. hydr. 



Oxygen gas 

 consumed by 

 a cubic foot. 



Gives 



Carb. acid. Water. 



Newcastle coal, 

 Ditto, last product, 



333-7gr. 

 169-5 



233-7 ! 99 fi 

 111-5 | 57-8 



1 1 10-3 



560 



817-3 

 400 



621 

 384-9 



The inferior gas, also, probably contains carbonic oxide ', 

 for the quantity of oxygen gas, actually consumed, will be 

 found, on calculation, less than it ought to be, if the car- 

 bon were not already combined with a portion of oxygen. 



The quantity of water, which was generated by com- 

 bustion, was not determined experimentally, but is merely 

 estimated. It must be acknowledged that the decomposi- 

 tion of the inflammable gases cannot lead to unques- 

 tionable results, until the proportion of water, produced 

 by their combustion, be also accurately ascertained. With 

 the view of effecting this, I have already spent, much 

 time, and employed many contrivances, none of which 

 have satisfactorily answered the purpose for which they were 

 intended. 



7. There appears to be a considerable difference in the 

 specific gravity and'combustibility of gas from various speci- 

 mens of coal, even when taken at similar periods of the di- 

 stillation. The coal from Merthyr In South Wales, which 

 burns without flame or smoke, yields a gas which contains, 

 in an equal volume, scarcely half as much combustible mat- 

 ter as the gas fromWigan canriel. This will probably be 

 found to be the case with respect to all coal of similar qua- 

 lity, among which may be reckoned the Kilkenny coal. The 

 most important difference among the varieties of this mi- 



T 3 neral, 



