GASOLENE 17 



just what we wanted? It would be composed only of 

 hydrogen and carbon. It should give on complete 

 combustion only water and carbonic dioxide, innocuous 

 final products, already in the air. It should contain 

 no ash; leave no solid residue to foul the cylinder. It 

 should contain just as much hydrogen and as little car- 

 bon as possible. It should be a liquid at ordinary tem- 

 peratures but be easily converted to a gas for combus- 

 tion. It must not rot on keeping or freeze on cooling. 

 It should not contain water because that reduces the 

 heating power. Preferably it should look nice and 

 clear like water and not stain things. It must not have 

 a disgusting odour like carbon disulfide, though we will 

 not insist upon absolute odourlessness or a pleasant 

 perfume. 



Now all these requirements are found in gasolene and 

 in that only. The compounds of carbon and hydrogen 

 are constructed like a chain. Each link is composed 

 of one carbon atom connected with two hydrogen atoms. 

 The first of the series and the simplest possible is me- 

 thane, CHU, but that is a gas. So is the next, but when 

 we get along to the fifth and sixth members of the 

 methane series we get to liquids of the gasolene group. 



JUST WHAT Is GASOLENE ? Gasolene is not a single 

 and uniform substance. You who use it know that it 

 varies in quality, especially in volatility. It is simply 

 the lightest part of petroleum, the part that comes over 

 at the lowest temperature when the distillation of 

 petroleum begins. Next comes kerosene, and then the 

 heavy lubricating oils, and later vaseline and paraffin, 

 le asphalt is left behind in the still. Formerly, when 



