15 _ Remarks on Professor Eaton’s Coneriniibeatstihe é 
ees, 
rocks, with stones not mineralized ;” and ‘ Papier ritus 
or eSpost: -diluvian accumulations of mud, san re 
Nay, even Werner himself made the following division of 
alluvium which must have had a reference to “ the r 
ages of different layers.” 
~ “1. Mountain alluvial formations. 
a. On the summits of mountains 
b, On the sides of mountains and at the foot of moun- 
tain ranges. 
2. Alluvial formations of low or flat lands.” 
If then we are guilty of neglect, it is neglect of Mr. 
oe s division of alluvium into “ primary and secondary 
alluvion.”” Butour object was not to notice all the attempts 
“ 
-=. 
to divide this stratum that had been made by ad sa = 
to notice that which appeared to us the best 
believed, and still believe, that Mr. Scnebeons’ has been so 
accordance with those distinctions that actually exist in 
nature. We believe too, that until geologists adopt these 
terms, their descriptions of the newest formations will be 
extremely vague and unintelligible. Mr. Eaton’s primary 
alluvion is distingushed from his secondary alluvion by the 
absence of vegetable remains, in the former. Now sup- 
e he comprehends in the general term alluvion, all the 
unconsolidated strata—which extensive meaning we believe 
has usually been affixed to the term—and let us inquire what 
part of these strata will be included under his primary allu- 
vion. For convenience, let us use the terms employed by 
Mr. Conybeare, i in the work under consideration, as our 
uide in answering this question. No doubt will exist but 
his alluvium is comprehended in Mr. Eaton’s secondary 
tute the greater part of what is usually called alluvion. 
e come next to the alternations of the fresh water and 
upper and lower marine formations, a few of the varieties of 
which are not consolidated; yet in nearly all of them, if 
tot all, vegetable remains occur. Certainly they occur in 
great quantity in the London Clay and Plastic Clay, which 
lie beneath the formations just mentioned, and therefore, if 
