oe 
Association of American Geologists and Naturalists. 221 
hard agates and chalcedonies, the opals, the jaspers, and the chalk 
‘flints, bear ample testimony, by their included organic forms, that 
the time was, when they were not in existence, and these evan- 
escent beings, the fossil animalcule, enjoyed their day or hour of 
life, before these beautiful minerals were formed. 
In the same manner, the vast beds of tertiary, of chalk, and 
many of the secondary limestones disclose, under the searching 
_ Scrutiny of the microscope, a world of minute organic forms, that 
once lived in that earlier ocean by whose waves their elegant 
Structures were first sustained, and then broken down and com- 
minuted into an earthy edlonrcent powder, which, to the naked 
eye, appears almost impalpable. In similar circumstances, both 
in the cretaceous and tertiary strata of New Jersey and Virginia, 
(as observed by Professors Bailey and Rogers,) the microscope 
reveals to our eyes myriads of Foraminifera* or polythalamous 
shells—their divisions perfect, their delicate edges and processes 
in fine preservation, their porcelain varnish lustrous and beautiful, 
and still so inconceivably small, that thousands of them have been 
Seen to run, ina few minutes, through a pin-hole in a piece of 
paper.} 
The attention of geologists is now powerfully directed to the 
results of microscopic analysis, which will probably be carried 
back through the earlier aqueous rocks, and may not cease until 
we arrive within the domain of fire, nor perhaps even before 
We reach to rocks that have been in actual fusion, where, of 
course, we should expect that all traces of organization would 
be destroyed. Although we cannot assign a limit to these re- 
Searches, we are certain that one must exist, since, it is obvious, 
that mineral matter must have been first in the order of the cre- 
ation ; for no organized beings could have existed, until earth, 
waters, and air were provided, as the scene of their action, and 
to afford them the elements of nutrition. 
It appears from these instances, = eg takes a high 
rank among the physical sciences. eed, wh hile to a great ex- 
tent it involves a knowledge of aie er it repays the zealous 
explorer with a rich intellectual recompense, and affords to civili- 
7 * This Jour., Vol x1, p. 213. Prof. H. D. ae. oa on tects 
Prof. W W. B. Rogers's report on geology of Virginia, 1 
+ This later fact was observed by Mr. Lonsdale with respect to ihe chalk of 
England. — 
ee nag 
* 
