792 [ASSEMBLT 



giving ofi large quantities of sulphurous acid." A singular for- 

 mation of natural copperas, exists immediately below the " Wil- 

 mington Notch," on tlie bank of the Au Sable river. The impreg- 

 nated water oozing from the earth, forms a thick concretion upon 

 the rock, which may be removed in large quantities. It is adapt- 

 ed, in its crude state, to all the usual purposes of the artificial 

 sulphate of iron. I submitted a specimen of this ingredient to 

 Professor Salisbury, for examination, whose analysis gives the fol- 

 lowing results : 



" One hundred parts of dried, at 212'^ contains of 



Sulphur, 5.10 



Iron, 9.05 



Sulphuric acid, , 4.68 



Silica, 70.90 



Alumina, 2.50 



Lime, 4.70 



Magnesia, 0.70 



Potassa, 0.85 



Soda, . .. 1.21 



Chlorine,. * 0.11 



Phosphoric acid, trace 



99.80^' 



•' From the account of the extent of this deposit, Isee^no reason 

 why it may not become valuable for the purpose of manujfactu- 

 ring sulphate of iron, and sulphuric acid.'' 



Copper ore has recently been disclosed, many feet below the 

 surface, in the '^phosphate mine," and at another locality in 

 Crown Point. These indications cherish the expectation of find- 

 ing the ore in large deposits. Specimens submitted to Professor 

 Salisbury, afford the following very favorable analysis. The re- 

 sults indicate that copper may become an important commodity 

 in the metalic resources of the county. 



No. 68. No. 86. 



Copper,.. 44.50 46.70 



Iron, 21.30 10.45 



Sulphur,. 30.20 





It/r^-'-.o^' 



