EXCELLENCE OF NEWTON'S WORK. 243 



demand the greater attention. Not only this, but at the time of Newton's 

 work the microscope had been little applied to the study of the pre-Cambrian 

 rocks in this country. The geologist of to-day has not only Newton's report 

 to build upon, but those of the army of workers who in the past decade have 

 been engaged in a study of the crystalline schists. In this paper I have 

 necessarily emphasized differences, but I close with a feeling of admiration 

 for the general excellence and fidelity of Newton's report and Gilbert's 

 editorial skill. 



XXXtl — Bum,. Geol. So* . Am., Vol. 1, I88i>, 



