38 
[Assembly 
Upwards of twenty boxes of minerals, belonging chiefly to the above 
class, were obtained during the past season, and are deposited in the geo- 
logical rooms, in the capitol. But as I proposed to confine this report 
principally to our useful minerals, I shall at present notice only those 
which can properly be arranged under this head. 
Magnesian Minerals. 
62. Several minerals are found on Staten-Island, and also in other 
parts of the State, which, in consequence of their containing large pro- 
portions of magnesia, may properly enough for my present purpose be 
grouped together under the name of magnesian minerals. Some of these 
may be turned to account in the arts. 
The mineral called serpentine constitutes the principal ridge of hills 
on Staten-Island, extending from New-Brighton to a little west of 
Richmond, a distance of eight miles. It assumes a great variety of as- 
pects, from black to nearly white, and from compact to earthy. Some 
of the talcy varieties are commonly known by the name of soap stone. 
Talc, carbonate of magnesia and hydrate of magnesia abound in it, and 
the rock might be used with profit in making magnesian salts.* 
The suggestion here made in regard to the preparation of magnesian 
salts from the minerals so abundant on Staten-Island, is deemed of great 
consideration. These minerals contain from one-third to two-thirds of 
their weight of magnesia, as will be seen from the following results of 
their analysis. 
Prof. Mather's Report for 1838. 
