In a paper recently read before this Society the ultimate analysis was used as a means of distinguishing between the various species of carbonaceous minerals, it being shown that, by a simple graphical method, these minerals could be classified in five groups, viz.: coals, sub-cannels, cannels, parafila shales, and torbanites. Minerals from all these groups are past, present, or prospective raw materials for oil-distillation, for which purpose, indeed, the oil shales and torbanites are especially suitable. It is therefore of interest to inquire whether their yield of crude oil and the composition of these substances are related in a manner sufficiently definite to serve as a guide to those concerned in this branch of technology.