"PRINCIPLES OF OIL ACCUMULATION" 367 



never has been known to split a molecule of any kind; nor has 

 mere "mechanical energy." It will require an entirely new 

 concept of the molecule to assume that a mechanical shear can 

 cut a molecule. Only vibratory forces, like heat, light, electricity, 

 and subatomic radiations are now thought to be capable of penetrat- 

 ing molecules. The mechanical energy of McCoy's experiment 

 must have been transformed into one of these other forms of 

 energy before it could split the molecules of organic solids. 



The formation of oil is a process which results in a great increase 

 in the volume of the original solid material, which is converted into 

 new soKds, liquids, and gases. Pressure therefore is a condition 

 which might be expected to retard rather than accelerate the 

 process. In fact, the distillation experiments by Engler have 

 shown that pressure retards the thermal dissociation of fats. The 

 principal effect of pressure in this connection is to cause an inward 

 shift in the point of splitting within the solid organic molecules. 

 High pressure causes the splitting to take place farther frorn the 

 surface of the molecules, resulting in the formation of less gas and 

 coke and of more of the intermediate or liquid products. The 

 same phenomenon also appears to rule the operation of the high- 

 pressure stills of cracking plants, decreasing the amount of gas 

 and residue in the product, and increasing the amount of gasoline, 

 and under certain conditions increasing the yield of kerosene. 

 Therefore high pressure in the rocks probably is a useful and 

 essential condition for the formation of oil. It is not, however, 

 the main cause of the formation of oil. There is nothing in this 

 experiment to indicate that heat is not the principal agent that 

 splits solid organic molecules into gases, oils, and carbon-rich 

 residues such as asphalt. 



A slight increase in temperature may be enough to initiate the 

 process, after which the release of the endothermic heat of formation 

 evolved by the splitting of the first molecules would increase the 

 temperature of adjacent molecules. Thus, when once initiated by 

 any cause, the process of thermal dissociation of sohd matter into 

 oil, gas, and black residue would tend to perpetuate itself and to 

 increase, like spontaneous combustion, as long as there was an 

 abundant supply of endothermic organic matter present. 



