SCIENCE IN AMERICA. 313 



counter the southwestern Atlantic winds, and deprive them of their 

 vapor. During the glacial epoch this vapor was precipitated as snow, 

 which slid down the slopes, while every valley and recess kept up a 

 constant supply of glaciers into Glen Spean, tilling it to an ever- 

 increasing height. There would of course be ice in Glen Spean, and 

 water to the north of it, as the winds in passing north would be partly 

 dried and warmed by the liberation of their latent heat. As long 

 as the supply was in excess of the consumption, the dams closing the 

 glens would increase in height. As the weather grew warmer, the 

 opposite would be true. For a long time the conflict would continue, 

 retarding indefinitely the disappearance of the barriers, but the ice in 

 the end would have to give way. " The dam at the mouth of Glen 

 Roy, which probably entered the glen sufficiently far to block up Glen 

 Glaster, w T Ould gradually retreat. Glen Glaster and its water-shed 

 being opened, the subsidence of the lake 80 feet, from the level of the 

 highest to that of the second parallel road, would follow as a conse- 

 quence." " In presence, then, of the fact that the barriers which stopped 

 these glens to a height, it may be, of 1,500 feet above the bottom of 

 Glen Spean, have dissolved, and left not a wreck behind; in presence 

 of the fact insisted on by Prof. Geikie, that barriers of detritus would 

 undoubtedly have been able to maintain themselves had they ever 

 been there; in presence of the fact that great glaciers once most cer- 

 tainly filled these valleys that the whole region, as proved by Mr. 

 Jamieson, is filled with the traces of their action the theory which 

 ascribes the parallel roads to lakes dammed by barriers of ice has, in 

 my opinion, an amount of probability on its side which amounts to a 

 practical demonstration of its truth." 



-" 



SCIENCE IN AMERICA. 1 



By Peoitessob JOHN W. DEAFER, M. D., LL. D. 



GENTLEMEN, Members and Associates of the American - 

 Chemical Society : In accordance with the plan of the Ameri- 

 can Chemical Society, I am called upon to address you this evening. 

 I have to congratulate you on its successful establishment, and its 

 prospect of permanent success. 



Let us consider some of the reasons which would lead us to expect 

 that success, not only for our own, but also for other kindred societies. 

 The field' of Nature is ever widening before us, the harvest is becom- 

 ing more abundant and tempting, the reapers are more numerous. 

 Each year the produce that is garnered exceeds that of the preceding. 



1 Inaugural address before the American Chemical Society, delivered at dickering 

 Hall, New York, November 16, 1876. 



