LIBRA 



The Ottawa Naturalist. 



Vol. IX. 



OTTAWA, SEPTEMBER. 1895. 



No. 6. 



CRYSTALS.* 



By W. F. Fkrrier, B.A.Sc, F.CS. Lithologist to the Geological Survey 



of Canada. 



I have nothing original to offer you on this subject, nor are my 

 remarks intended to constitute a lecture on crystallography, but merely 

 to bring to your notice some interes.ing facts with regard to those won- 

 derful forms which we call crystals, and more especially to trace out the 

 progress made in the study of them since the earliest times. The sub. 

 ject is so vast that it will only be possible for me to call attention to some 

 of the more prominent and interesting facts, which constitute, as it were, 

 the milestones along the road of our knowledge of the subject. 



At the outset we are confronted with the question " What is a 

 crystal ? " 



So many definitions have been given that it is somewhat difficult to 

 select one which is expressed in simple terms and at the same time is 

 comprehensive and accurate. 



E. S. Dana says : " Structure in Inorganic nature is a result of 

 mathematical symmetry in the action of cohesive attraction. The 

 forms produced are regular solids called crystals ; whence morphology 

 is, in the Inorganic kingdom, called CRYSTALLOLOGY. It is the science 

 of structure in this kingdom ot nature." 



He subdivides the subject as follows : 



( treating of forms resulting from 

 } crystallization. 



Crystallography 



Crystallology 



I 



^ Crystallogeny 



j treating of the methods of making 

 - crystals, and the theories of their 

 ( origin. 



(Read before the Ottawa Field Naturalists' Club, Dec. 20th. 1894.) 



