192 Proceedings of the Royal Society of Edinburgh. [Sess. 
between 200° and 250° C. in a current of dry nitrogen, and collecting the 
water evolved in a calcium chloride tube. Little or no oil was given off 
at this temperature, but to secure that none was retained in the calcium 
chloride tube a current of dry air was passed through it for twenty minutes 
after each experiment. In a distillation of torbanite under a pressure of 
1 mm., no perceptible quantity of oil was produced until a temperature of 
380° C. had been attained by means of an electric furnace. The correction 
thus applied in no case exceeded 0T5 deduction from the hydrogen per- 
centage, or L35 addition to the ash percentage. The detailed analyses are 
given below along with the works’ yield of oil and ammonium sulphate 
where these are known. The samples of Dunnet shale are from a bore at 
Broxburn, each one representing one foot of the seam in vertical thickness 
from the top downwards. The last two analyses are those of specimens of 
“ burnt ” shales occupying the positions of the “ Maybrick ” and “ Curly ” 
seams of the Pumpherston shales in a bore at Knightsbridge, and described 
by R. G. Carruthers ( Oil-Shales of the Lothians, 1912, p. 88). He puts 
forward the theory that these shales have been “ burnt ” or rendered useless 
not through the proximity of any igneous rock, but through the oil having 
been distilled off from them by the heat evolved from the oxidation of 
pyrites dust in the underlying tuff beds. 
The relatively high percentage of oxygen in sample 12 might be con- 
sidered to lend support to this theory, but this is somewhat negatived by 
the much lower oxygen percentage in sample 13. The high nitrogen 
percentages in each show, however, that whatever changes the shale has 
undergone, the nitrogenous matter has heen the last to be affected. 
List of Shales Analysed. 
1. Dunnet — Top foot (Broxburn). 
2. ,, 2nd „ 
3. „ 3rd „ 
4. ,, 4th 
5. „ 5th „ 
6. „ 6th „ 
7. Camps — Flat portion (Pumpherston). 
8. Camps — Inclined portion (Pumpherston). 
9. Broxburn (Pumpherston). 
10. Torbanite (Armadale). 
11. Australian Commonwealth. 
12. “ Burnt ” Shale — “ Maybrick ” (Knightsbridge). 
13. “ Burnt ” Shale — “ Curly ” (Knightsbridge). 
