of Hydrocarbons and their Mixtures. 



121 



it produces (Chem. Journ. 1884, p. 38.) It occurred to 

 me at once that the carbon of the marsh-gas is present, and 

 ought not to be neglected. In fact it certainly has an illu- 

 minating value, as has been shown by P. Frankland himself, 

 who found it (I. c. p. 3\)) to have an illuminating-power of 

 several candles. I cannot therefore think that the carbon in 

 the marsh-gas should be neglected. If we regard the carbon 

 in flame as being in a sense in solution in the hydrogen, until 

 it is precipitated in the luminous form, it is clear that all the 

 carbon present must count. 



This consideration led me to a method of representing the 

 connexion between illuminating-power and composition, 

 which depends primarily on the assumption that the illumi- 

 nating-power is a function of the ratio of carbon to hydrogen. 

 It seemed also probable that the carbon density might be 

 involved. 



The C/H ratio employed might be more correctly written 

 m/n, where C m H„ is considered. But it is perhaps more 

 convenient to speak of it as the C/H ratio. It will be repre- 

 sented by t r, and measured along the horizontal axis. The 

 candle-power is represented by ?/, and measured along the 

 vertical axis. 



First I took the series of mixtures of ethylene and hydro- 

 gen which is given at Chem. Journ. 1 884, p. 34. The C/H 

 ratio was calculated, also the carbon density. The table then 

 assumes the following form : — 







Ethylene 



and Hydrogen. 





Per cent. 



Carbon 

 Density. 



C/H ratio. 







C.P. 



y 



C 2 H 4 . 



H 2 *. 





X 



Direct. 



Indirect. 



100 







2 



•5 



68-5 



65 



77-55 



2245 



1-55 



•437 





54-58 



68-39 



31-61 



1-37 



•406 





49 37 



53-58 



4642 



107 



•349 





39-21 



35-47 



64-53 



•709 



•262 



i 



30-85 



26-08 



73-92 



•522 



•207 





22-84 



13-37 



86-63 



•267 



■118 





6-73 



* I have added the subscript 2 here, 

 the calculations. 



It has to be taken count of in 



