54 FIRESIDE SCIENCE. 



manipulation can a drop of kerosene be obtained 

 from coke, or from anthracite coal ; they are both 

 residuums, or results of an exhaustive chemical 

 change. The anthracite coal-beds may be regarded 

 as the coke, remaining after the distillatory process, 

 which produced petroleum, was completed. Arti- 

 ficial coke, by pressure and moisture, can be made 

 to resemble anthracite in its physical aspects. A 

 vast number of interesting questions arise at this 

 point regarding the probable origin of petroleum, 

 its nature, and distribution ; but we must hasten 

 to consider the chemical changes to which a pint 

 of kerosene is subjected after being placed in a 

 lamp and burned as a source of artificial illumina- 

 tion. 



Kerosene is a pure hydrocarbon liquid ; that is, 

 a liquid made up of the elements hydrogen and 

 carbon. Both of these are combustible, or possess 

 a strong affinity for oxygen ; and associated to- 

 gether, as in kerosene, they afford a luminous flame 

 when burned by uniting with oxygen. The results, 

 or products, of combustion differ in no respect from 

 those which proceed from other organized carbon- 

 aceous bodies, being mainly water and carbonic 

 acid. 



Estimating carefully the amount of light afforded 

 by a measured quantity of kerosene, and contrast- 

 ing it, in price, with gas, sperm oil, wax candles, 



