UTAH ACADEMY OF SCIENCES 213 
Many varying products can be obtained from the 
destructive distillation of kerogen. The character and 
quality of the materials produced depends greatly on 
the temperature to which the vapors produced from the 
kerogen are heated within the retort. The duration of 
the time that the vapors remain in the retort seems also 
to have a decided decomposing action on the vapors and 
resulting products. It does not follow, however, that all 
shales will yield the same products when heated simi- 
larly, because shales differ physically, and the oil-forming 
material may be of an entirely different origin in different 
shales. The organic, matter of the oil-shales of the 
eastern part of the United States, occuring in the Devo- 
nian formations, is made up almost entirely of spore mat- 
ter, as are also some of the Scotch shales. The western 
shales of the Green River formation seem to be more 
complex, and contain, in addition to the spore matter, 
resenic and cellulosic materials. Some of the cannel 
coals and cannel slates of the east belong to this latter 
class. All of these give different oils under the same 
retorting conditions, which facts have been brought out 
by much experimental evidence. However, information 
is in no wise complete as to whether the principal cause 
of difference is due to the character of the included 
organic material, or to the percentage and character 
relation of the minerals associated with it. 
INFLUENCE OF PHYSICAL STRUCTURE OF SHALE ON 
DISTILLATION PRODUCTS. 
It is quite probable that in all shale retorting 
methods, the actual decomposition range for a given 
shale, begins at comparatively low temperatures, but the 
ultimate products produced owe their characteristics prin- 
cipally to chemical and physical reactions occuring while 
the products of distillation are passing from the primary 
decomposition state, which is probably a viscous fluid, into 
the vapor state, or while in the vapor phase. This alter- 
ation from the primary decomposition state is evidently a 
cracking phenomenon and the products will be influenced 
