MAGNESIAN MINERALS. 



67 



MAGNESIAN MINERALS. 



Several minerals arc found on Staten Island, and also in other parts of the State, which, in 

 consequence of their containing large proportions of magnesia, may properly enough for my 

 present purpose be gi-onped together under the name of magnesian minerals. Some of these 

 may be turned to account in the arts. 



The mine'ral called serpentine constitutes the principal range of hills on Staten Island, ex- 

 lending from New-Brighton to a little west of Richmond, a distance of eight miles. It assumes 

 a great variety of aspects, from black to nearly white, and from compact to earthy. Some of 

 the talcy varieties are commonly known by the name of soapstone. Talc, carbonate of mag- 

 nesia 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 worthy of great consideration. These minerals con- 

 tain from one third to two thirds of their weight of magnesia, as will be seen from the following 

 results of their analysis. 



TABLE- 



SJioiving the composition of several Magnesian Minerals, especially in refereyice to the 

 proportion of Magnesia ivhich they contain, in \Q0 jnirts. 



No. 1. From Staten Island, and Hoboken, New-Jersey. 

 No. 2 and 3. From the same localities. 



No. 4. From Staten Island, Stony Point, Rockland Co. etc. 

 No. 5. Found in various parts of the State. 



The magnesia contained in either of these minerals would furnish, by combination with 

 sulphuric acid, upwards of two hundred parts of sulphate of magnesia or Epsom salts, in the 

 form in which it is ordinarily sold in the shops. Moreover, the sulphate of magnesia, thus 

 obtained, may be decomposed by carbonate of soda or potash, and produce carbonate of mag- 



♦ Mather. Nm--Ynrh Geolociial Reports, 1S38. 



t Wachmeister. Sillimnn's Journal, XVIII. 167. 



II By my analysis. The specimen was from .Staten Island. 



Part I. 8 



t Bruce. American Minemlogical Journal, I. 26. 

 i} Nuttall. SiUinians Journal, IV, 17. 

 % Thomson.' Outlhics of Mmeralogi/, <^c. 



