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that occasion, I will further endeavour to take a view of the last 
advances which geology has made in the other quarters of the 
globe, whether in the numerous British Colonies, or in the United 
States, or in those parts of Asia and Africa which have been re- 
cently explored. 
In respect to American geology, I have, however, to notice two 
short communications to ourselves by Mr. Henwood ; the first on 
the beds near Lockport and at Rochester, in which he sustains, by 
aid of a series of organic remains presented to the Society, the views 
respecting those strata entertained by American geologists; and the 
second on parts of New Brunswick, particularly the coal-measures 
which extend over a wide area, and rest in some places upon granite 
and in others upon schistose rocks; and he shows that though gra- 
nite veins penetrate the slate, not one is to be found in the coal- 
measures: hence he infers, that the schists are the oldest rocks of 
the country, and the coal-measures the newest. 
THE GLACIAL THEORY. 
The last subject I will advert to is that of glacial action, which 
has recently occupied the thoughts of many geologists. From a 
study of the Alps, where Venetz and Charpentier led the way in 
showing that a connexion existed between the erratic blocks and 
the advance of glaciers, Professor Agassiz has deduced a glacial 
theory, and has endeavoured to generalize and apply it.even to our 
own countries, in which effort he has been supported by my prede- 
cessor in the Chair. In the following observations, I will endeavour 
to point out what new materials have been brought forward, abroad 
and at home, to enable us to reason correctly on this difficult ques- 
tion, and I will then suggest some essential modifications of the new 
hypothesis. 
As propounded by Agassiz, the glacial theory, even in its appli- 
cation to the Alps, has met with an opponent in the person of Pro- 
fessor Necker de Saussure. In the first volume of a work which he 
is now publishing, M. Necker treats, in great detail, the whole sub- 
ject of superficial detritus connected with the northern and western 
watershed of the Alps, and gives us the fruits of many years of ob- 
servation. Adding very considerably to the list of phanomena of 
transported inaterials collected by M. A. de Lue, he takes his own 
illustrious ancestor, De Saussure, as his model, and following in the 
track of the historian of the Alps, he endeavours to enlarge and 
improve upon that great observer’s suggestions. Pointing out the di- 
stinetions between two classes of detritus, viz. one of high antiquity 
and another of modern date, M. Necker contends that the enormous 
masses of the ancient drift or diluvial detritus have a direct con- 
nexion with the actual configuration of the surface, because the 
chief part of them has been derived from the centre of the chain, 
the flanking and lower mountains, and even the strata on which it 
rests, having contributed comparatively little to the great advancing 
body. Examining the high valleys about Chamouni and the foot 
of Mont Blane, and finding massive walls from 300 to near 600 
