54 Pierce on Amianthus and Carbonate of Magnesia, 



Art. IV. Carbonate of Magnesia, and very uncommon 

 Amianthus, discovered near J^ew-York. — Extract of a 

 Letter from Mr, James Pierce to the Editor, 



New-York, May 18, 1818. 



DEAR SIR, 



J. FORWARD you specimens of straw and rose-coloured 

 amianthus I recently met with on Staten-Island, which I de- 

 tached, in strips, from a rock ; it not appearing, as is usual, in 

 veins. It breaks up like flax, and may be spun and wove 

 without the aid of moisture ; and in respect to tenacity, flexibi- 

 lity, and length of fibre, it may be considered the best found in 

 this country, and perhaps equal to any hitherto discovered. 

 Staten-kland exhibits many minerals worthy of examination. 

 I subjoin, as requested, the following geological descrip- 

 tion, &,c. 



Hoboken, where I discovered native carbonate of" magnesia, 

 is situated opposite the city of New-York, on the western or 

 New-Jersey bank of the Hudson. It is a primitive, insulated 

 elevation, with a nucleus of serpentine ; the ground gradually 

 descends in every direction except on the river side, where 

 mural precipices of serpentine rock are observed, extending 

 about 100 rods parallel with the water, and elevated from 60 

 to 100 feet above its level. The carbonate of magnesia I found 

 in horizontal veins of nearly two inches in breadth, and of un- 

 known depth, in a midway region of this serpentine ledge ; I 

 extracted a considerable quantity with a spoon. When first 

 taken out it was soft, white, and very slightly adhesive, from 

 a little moisture ; but, when dry, fell to powder without fric- 

 tion. The nature of the mineral I immediately conjectured, 

 and treated it with diluted sulphuric acid, in which it entirely 

 dissolved with eflfervescence, forming a bitter fluid, and 

 leaving no sediment. Upon evaporation, well-defined crystals 

 of Epsom salts were formed. It differs little from the 

 manufactured carbonate of magnesia of the shops ; but is 

 rather a super than a sub-carbonate. It has befen analyzed by 



