36 THE DAWN OP LIFE. 



logical and palEeontological knowledge^ and the sur- 

 veys previously made, whereby the age and distribution 

 of the Laurentian rocks and the chemical conditions 

 of their deposition and metamorphism were ascer- 

 tained. 



The first specimens of Eozoon ever procured, in so 

 far as known, were collected at Burgess in Ontario 

 by a veteran Canadian mineralogist. Dr. Wilson of 

 Perth, and were sent to Sir William Logan as mineral 

 specimens. Their chief interest at that time lay in 

 the fact that certain laminas of a dark green mineral 



Fig. 7. Eozoon mineralized by Loganite and Dolomite. 

 (Collected by Dr. Wilson, of Perth.) 



present in the specimens were found, on analysis by 

 Dr. Hunt, to be composed of a new hydrous silicate, 

 allied to serpentine, and which he named loganite: one 

 of these specimens is represented in fig. 7. The form of 

 this mineral was not suspected to be of organic origin. 

 Some years after, in 1858, other specimens, difi"erently 

 mineralized with the minerals serpentine and pyrox- 



