THE HAMILTON ASSOCIATION. 1 65 



5. The present writer is not aware that the following has ever 

 been made generally known. On the Post-caenozoic clays (Erie 

 and Saugeen clays of our Geological Survey) the pine timber grown 

 is soft and easily workable, while that grown on the Medina clays 

 is hard and brittle. It is the intention of the present writer to pre- 

 pare a few slips of each for the microscope and to examine them. 

 The most plausible view appears Aat the larger percentage of silica 

 in the sandy soil has something to do with the state of the wood, 

 but it were safer not to speculate until observations have been made. 



