of Bitumens, and of Bituminous Shales. 161 
self, gave to dilute hydrochloric acid from fifty-three to fifty-eight 
per cent of carbonate of lime, besides a little magnesia and oxy 
of iron. The insoluble residue was snuff:-brown in color, and, 
when heated, gave off a bituminous odor. When ignited ina 
close vessel, it lost 12°6 per cent of volatile and combustible 
matters, and left a coal-black residue, which, by calcination in 
the open air, lost 8-4 per cent additional, making in all 21:0 per 
cent of volatile and carbonaceous matters, and left an ash-gray 
argillaceous residue. This shale however contained but a very 
small amount of bitumen, for, on treating the residue from a di- 
lute acid with boiling benzole, there was dissolved about one per 
cent of a brown bituminous matter. The residue, when heated, 
no longer evolved the odor of bitumen, but rather one like 
burning lignite, and still gave, by ignition in a close vessel, 11°83 
per cent of volatile and inflammable matters. When boiled 
With a solution of caustic soda, this was scarcely discolored. In 
Its insolubility, therefore, the organic matter of this rock re- 
sembles true coal, rather than lignite. Attempts have been 
made, on a large scale, to distill this calcareous schist of Col- 
lingwood, and it was found to yield from three to five hundredths 
of oily and tarry matter, besides combustible gases and water. 
Overlying the Hamilton formation in Western Canada are 
found biack pyroschists, which are supposed to be the equivalent 
of the Genesee slates of New York. A specimen from Bosan- 
quet lost, by ignition in a closed vessel, 12-4 per cent, and left a 
black residue, which was not calcareous. rtion in fine 
Powder was digested several hours with heated benzole, which 
took up 0°8 per cent of brown combustible matter. : si 
due, carefully dried at 200° F., then lost, by ignition in a close 
’ 113 per cent, and by subsequent calcination 11:6 addi- 
Cent of oily hydrocarbons, besides a large quantity of inflam- 
mable gas, and’a portion of ammoniacal water. 
the chief organic remains to be detected are Graptolites, with a 
few Brachiopods and Crustaceans. No traces of terrestrial veg- 
tation are known to have existed at that time, nor do the schists 
Contain the evidences of any marine plants. The pyroschists 
of Mesozoic age, in several parts of Europe, contain, on the con- 
