198 REPORT OF THE 



those cases where a bog lias grown with the growth and decay 

 of Sphagnum, or other bog mosses, the peat is often composed of 

 almost pure vegetable matter. In other cases, where the bog 

 has been periodically inundated, as around the margins of some 

 lakes and ponds, more or less of earthly sediment will be found 

 mixed with the peaty materials. A large proportion of our 

 principal peat bogs, however, will compare favorably in purity 

 with those in foreign countries, to which I have already alluded. 



It will of course be inferred that the bed of lignite which I 

 have described as occurring on the shore of Grand Traverse 

 Bay, possesses all. the capabilities of ordinary peat. Should 

 4he spontaneous flow of petroleum from the rocks ever be ma- 

 terially diminished, the same product may be very cheaply dis- 

 tilled, as is done in foreign countries, from lignite and peat as 

 w^ell as from coal. 



Although it might be better to "speak of Rock Oils or Petro- 

 leum under a distinct head, still the subject is here naturally 

 introduced, and I proceed to append the few remarks which! 

 have to offer on this subject. 



The distillation 'of bituminous shales and mineral bitumens 

 is carried on to a g; eat extent both in England and on the con- 

 tinent. To this class of matters belong the so-called Boghead 

 and cannel coals, as well as the bituminous minerals of various 

 parts of Fiance and Switzerland. Here belongs the black bitu- 

 minou". shale of Canada West, and Thunder and Grand Traverse 

 Bays in this State, which will undoubtedly prove uncommonly 

 rich in bituminous matter. Indeed, the abundant spontaneous 

 distillation from shales of the same age, which has supplied the 

 oil wells of Pennsylvania and Ohio, is an evidence that the 

 products of artificial distillation would prove correspondingly 

 rich. These substances yield, in general, the same products as 

 peat. The amount of paraffine, however, is said to be less, and 

 the residue left from distillation is, unlike that from peat, com- 

 paratively worthless. A yield of five per cent of bituminous 

 matter qualifies the shales in France to be economically worked. 

 The yield of our shales has never been accurately ascertained. 



