REPORT OF EXECUTIVE COMMITTEE. 
35 
containing an admixture of various mineral deposits in a pow¬ 
dery state, or in lumps which are pliable and crumble down on 
exposure, even though they contain no lime whatever. Prop¬ 
erly speaking, marl is a natural mixture of carbonate of lime, 
in some of its forms, with clay, sand, or the peaty matter of 
marshy lands, or with two or more of these substances at the 
same time. There are, therefere, several varieties of marl, 
such as chalk-marl, clay-marl, sandy-marl, peaty-marl, and 
shell-marl. 
Several of these varieties occur in this country, but there 
appears to be a lack of appreciation of their value as manu- 
rial substances, and consequently hundreds of extensive beds, 
though known to their owners, are yet unworked. In the 
Eastern and Middle States, where the agriculturist has not an 
unlimited area of virgin lands which he may occupy as the old 
lands fail in fertility, the green sand-marls of New Jersey, 
Delaware and Maryland, and the clay and shell-marls of New 
England, are coming into use. But in the West, and in our own 
State, notwithstanding the evidence that our soils, however rich 
and fertile, originally, cannot bear continued cropping without 
deterioration, vast quantities of this valuable mineral manure 
lie unimproved. 
Most of the Wisconsin marls are of the clay and shell vari- 
ties. The former, with a proportion of shelly matter almost 
sufficient to entitle it to the name of shell-marl, is found 
on the bottom of a great many of our lakes, and as a part of 
the mucky mass of the alluvial deposits of our numerous dry 
marshes. It is also found in large quantities in the crevices of 
the Lead Mines. A sample of this red crevice clay-marl taken 
from diggings near Shullsburgh, was analyzed by Dr. Hayes, 
at the instance of Prof. Daniels, and found to contain: 
Water,.12.20 per cent. 
Silicate of Alumina,.49.20 “ 
Oxide of Iron,. 8.80 “ 
Carbonate of Lime,...22.60 “ 
The shell-marls, properly so called, also abound in many 
parts of this State. These, as the name indicates, consist 
