Native Copper of Wallingford. 55 



Professor Mitchill, who found it exclusively composed of mag- 

 nesia and carbonic acid. Carbonates of magnesia, hitherto 

 discovered, have been, I believe, found impure, and in a state 

 of rock, requiring chemical process to render them service- 

 able ; this is, perhaps, fit for immediate use. When I first 

 mentioned the discovery to mineralogists, they were incredu- 

 lous, supposing it did not natively exist in this state, but I con- 

 vinced them by uniting it with sulphuric acid. 



The specimen of amianthus, referred to in Mr. Pierce'* 

 communication, is uncommon. The fibres measure from 12 

 to 15 inches in length, and are as soft and flexible as fine 

 human hair. 



It Will be remembered, that in the rocks at Hoboken, Dr. 

 Bruce discovered the hydrate of magnesia, or magnesia com- 

 bined with nothing but water, in the proportion of about 70 

 per cent, of magnesia. This discovery gave a new and inter- 

 esting species to mineralogy ; it is now admitted in the syste- 

 matical works on mineralogy. 



Mr. Pierce's discovery is not less interesting ; and we pre- 

 sume he will be deemed correct in the opinion, that pure na- 

 tive carbonate of magnesia has not been discovered before. The 

 serpentine of Hoboken, then, is memorable for affording these 

 two new species. 



Art. V. Native Copper. 



JlNBruce's Journal, (Vol. I. p. 149.) mention is made of a 

 remarkable piece of native copper, found near New-Haven 

 many years ago, and weighing about 90lbs. 



We have now to add, (and the fact is, indeed, mentioned 

 in Cleaveland's Mineralogy,) that another piece has been 

 recently found half a mile west of the Hartford turnpike 

 road, opposite the town of Wallingford, and twelve miles 

 from New-Haven. It was turned up in ploughing to repair a 



