DESCRIPTION OF THE COLLECTIONS. 
GEOLOGICAL COLLECTIONS. 
GEOLOGICAL SKETCH. 
Geology teaches us the structure of the Earth, how it was 
formed, the different phases through which it has passed, and with 
J'alceontology (a study of the fossil organic remains found im- 
bedded in the rocks) gives us a record of the different events in 
its history, and of the various races of animals and plants which 
have lived on its surface, or in its seas. It also aids us in finding 
the home of the various metals, coals, salt, building stones, and 
other substances of economic importance which the earth contains. 
It shows us that the outer portion of the earth's substance is 
made up of a succession of layers of rock of different kinds and 
composition, superimposed one upon the other like the layers of 
brick or stone in the walls of a building, and that although at the 
present time they are mostly covered by loose surface material, as 
boil, sand, gravel or clay, and this again by a coating of vegeta- 
tion, that wherever the experiment may be tried, rock in beds is 
found within a few feet, or a few hundred feet of the surface. The 
structure of the rocks shows us, that, except in the case of volcanic 
rocks, they were made up of deposits of various kinds formed 
under water, as they are regularly stratified, or composed of thin 
beds, although in many places they have been changed by some 
subsequent action. In consequence of these varying conditions, 
they have been classed under two principal heads, namely, 
Stratified and Unstratificd. 
The Unstratified rocks comprise all volcanic rocks, such as 
lavas, traps, basalts, &c. The Palisades, on the Hudson River, 
and the Giant's Causeway, in Ireland, are examples of this kind. 
The Stratified rocks are classed as Melamorphic and Non- 
metamorphic. The former are those which have been changed by 
