1913-14.] The Organic Matter in Oil-Shales. 
197 
Discussion of Analytical Data. 
Strahan and Pollard have adopted the “ carbon-hydrogen ratio ” (C/H) 
as a basis for the classification of coals, and have found it to vary from 12 -9 
in “ per-bituminous ” coals to upwards of 30 in anthracites. A variation in 
a smaller degree can be seen in the shales, the limits in the above analyses 
being 5*96 and 8*14. In all cases the ratio is lower than in the coals. The 
analyses show that the organic matter varies considerably in constitution 
in different shales. The most interesting fact revealed, however, is the 
connection between the carbon-hydrogen ratio and the yield of oil. The 
law would seem to be established that the yield of oil varies directly as the 
percentage of organic matter , and inversely as a function of the carbon- 
hydrogen ratio. This is strikingly shown by comparing analyses 3 and 4, 
where the same oil yield is obtained from the two samples, the excess of 
2*4 per cent, of carbon in 4 being neutralised by its higher carbon-hydrogen 
ratio of 7*57 as compared with 7*38 in 3. It is still more evident on a 
comparison of Nos. 7 and 8, where the oil yield in the latter is actually 1*5 
gallons more than in the former, although the carbon percentages are 10*13 
and 21*96 respectively, the explanation being that in 8 the carbon-hydrogen 
ratio is only 5*96, whereas in 7 it is comparatively high, viz. 7*68. It is 
thus shown that the all-important factor in shale analysis is the determina- 
tion of the relative percentage of hydrogen present, and that an approxi- 
mate analysis of a sample into volatile matter, coke, and ash may not shed 
so much light on its oil-producing properties as an ultimate carbon and 
hydrogen analysis. 
Action of Solvents on Shale. 
Mention has already been made of the fact that very little is extracted 
from shale by the common organic solvents. Dichlorhydrin, a high boiling 
solvent (b.p. 174° C.) was tried without success, but pyridine (b.p. 117° C.) 
was found to be an effective solvent. 
The Committee on Explosions in Mines (2nd Report, 1912) has investi- 
gated the solubility of coals in pyridine and shown that quantities of extract 
may be obtained varying from 3*7 to 38*8 per cent, on the ash-free dry coal. 
Torbanite and Broxburn shale were both completely extracted with pyridine, 
and it was found that 4*92 and 3*29 per cent, respectively of the ash-free 
dry shale was dissolved. If then, as is suggested in the report of the above 
committee, the extracted material represents the resinous part of the coal 
(the small percentages are from semi-bituminous, and the high from bitu- 
minous, coals), it is evident that only a very small portion of the organic 
matter in shale is of a resinous character. 
