PETROL 295 



C represents a heavier benzine which often goes under the 

 indefinite name naphtha. 



D is lamp oil, known in different countries by various names, 

 such as kerosene, mineral colza, paraffin oil, etc. 



Paraffin wax is a familiar solid used for making candles and 

 for other purposes. Mixtures of solid paraffin with some of the 

 liquid members of the series in different proportions constitute 

 machine oil used for lubrication, and vaseline a well-known 

 semi-solid or jelly-like substance used also for protecting metals 

 from rust and corrosion, and as an ointment or dressing in surgery. 



It is unnecessary to dwell on the purposes to which all these 

 and other special fractions of petroleum are applied. Motor 

 spirit alone would occupy many pages in the discussion of the 

 important questions involved in the various suggestions which 

 have been made as to possible substitutes. Of these the only 

 liquid which, in the event of deficiency, appears likely to be 

 available is alcohol. 



ORIGIN OF PETROLEUM 



Everyone is familiar with the idea that common coal, in all its 

 different varieties, is a product of chemical change, taking place 

 through long geological periods, in masses of vegetable matter 

 accumulated in certain strata of the mineral matters forming the 

 crust of the earth. Concerning the origin of petroleum there is, 

 however, no such unanimity of opinion. Many speculations 

 have been put forward from time to time, and without entering 

 into much detail, these may be at once ranged under two main 

 divisions. 



The question is did natural oil result from purely chemical 

 processes taking place in the earth, or did it result from the 

 action of heat on the remains of organic beings, animal or 

 vegetable ? 



That rock oil may have been formed without the previous 

 existence of living things is the view which was promoted chiefly 

 by the famous Russian chemist Mendeleeff, and it has much to 

 recommend it. Thus some deposits of oil are found in the most 

 ancient Silurian rocks, where it is difficult to suppose a previous 

 sufficient accumulation of organic matter. 



The formation of hydrocarbons can be accounted for by 

 supposing that the interior of the earth consists largely of com- 

 pounds of carbon with such heavy metals as iron and manganese 



