16 THE CANADIAN NATURALIST. [Feb. 



their out-door employments. Besides moths, bats also had takea 

 up their quarters in this cave, and flew around, sadly disconcerted 

 by our intrusion. In the paper alluded to in the beginning of this 

 article, it was stated that if the water could be pumped out of 

 this cave, bones might be found at the bottom. I may just men- 

 tion, before concluding this brief description, that the cave is now 

 entirely free from water, and that no bones have been found as vet r 

 but a search into and amongst the loose soil at the bottom, may 

 be, and I think would be, well worth attempting. 



CONTRIBUTIONS TO LITHOLOGY.^ 



By T. Sterry Hunt, M.A. F.R.S. ; of the Geological Survey of Canada. 



• Introduction. 



In a recent paper on The Chemical and Mineralogical Relations 

 of Metamorphic Rocks (Silliraan's Journal [2], xxxvi, 214),f an 

 attempt was made to define the principles which have presided 

 over the formation of sedimentary rocks, and to explain the nature 

 and conditions of their alteration or raetamorphism. That paper 

 may be considered as to a certain extent introductory to the 

 present one, which will contain, in the first part, some theore- 

 tical considerations which it is conceived sho:;ild serve as a basis to 

 lithological studies. In the second part will be given a few 

 definitions which may serve to render more intelligible the clas- 

 sification and nomenclature of crystalline rocks ; while a third 

 part will contain the results of the chemical and mineralogical 

 examination of some of the eruptive rocks of Canada; and a 

 fourth, some examples of local metamorphism. The most of the 

 results appear in the recent published Geoloixy of Canada. 



I. Theoretical Notions. 



I have already, in other places, expressed the opinion that the 

 various eruptive rocks have had no other origin than the softening 

 and displacement of sedimentary deposits; and have thus their 

 source within the lower pDrtionsof the earth's stratified covering, 

 and not beneath it. The theory which conceives them to have been 

 derived from a portion of the interior of the earth still retaining 

 its supposed primitive condition of igneous fluidity, is in my 



* From Silliman's Journal Vol. xxxvii, page 248. 

 t Canadian Naturalist, Vol. viii, page 195. 



