[A^gEMBLY 
manure. In this light we regard this formation now, and recom- 
mend to those whose location is favorable, to make a trial of the 
marly deposite on their lands. Information on the use of the marly 
clays may be obtained from Rogers' report on the geology of New- 
Jersey, and from one of the late numbers of the Journal of Sci- 
ence. 
In concluding our brief remarks on the geological sections, we 
observe, that they serve only a general purpose; thus they may 
be said to furnish the key to the geology of the district, as by them 
we may learn the general formations, and their comparative ex- 
tent. But what may be called the subordinate formations, such as 
deposites of the different ores, as lead, copper, iron, zinc and the 
valuable combustibles, as peat and coal, require an examination of 
the square miles. They serve to make it possible, or rather they 
furnish evidence to the mind of the geologist, whether those valu- 
able substances are compatible with the general formations, and 
whether it is expedient to search for them or not. For nature has 
established unexceptionable laws in the deposites of minerals, and 
guided by them, we expect to find her rich stores only in certain 
formations. 
This is so substantiated by modern discoveries, that it will suf- 
fice barely to mention the following well known facts. All the 
coal formations are above the primary rocks; the different kinds of 
coal belong to distinct geological positions in the strata. Gold in 
this country appears exclusively to have been deposited on the tal- 
cose slate — the species of iron do not occupy the same rock. It 
is not true, however, that golden sands are always in the debris of 
talcose slate: or that coal is always to be found in the coal mea- 
sures at any place, but, the kind of rock being known, and its place 
determined in the series of formations, we are then prepared to 
say whether it is expedient to search for coal, iron, or any of the 
valuable metals. 
These remarks are made in consequence of repeated inquiries . 
made of us during the last season, and in fact almost every day, in 
relation to these points; and we have often been assured, that coal 
had been found in districts entirely primitive in their character, 
and so of many other things which would have been equally out 
of place, had their assertions been true. It is no unfrequent occur- 
rence in this country, for men to spend small fortunes at least, in 
