Geology^ ^c. of the Connecticut. 209 



in giving a list of the simple minerals, I do not intend to be 

 scrupulously confined to the region embraced by the map. 

 This mine is wrought in a bed in clay. For further partic- 

 ulars see Prof. Silliman's account of this ore, in the Journal 

 of Science, Vol. 11. p. 212. 



18. Mine of the same ore, in Kent, in Connecticut. 



This is found, like the last, in a bed in clay. See Vol. 

 II. of the Journal of Science, p. 216. 



19. Mine of Carbonate of Iron, in Kew-MUford, in Connecti- 



cut. 



This exists in a vein, in ejneiss ; and its gangue is quartz. 

 See Journal of Science, Vol. II. p. 226. 



20. Bed of Bog Iron Ore, in New-Brainiree, in Massachu- 



setts. 



This ore is not uncommon along the Connecticut; but I 

 have never examined a bed of it, except in Nevv-Braintree, 

 in Massachusetts. It lies in a valley, in a country of gneiss, 

 only a few feet below the surface ; and has been explored 

 to a considerable extent. 



21. Mine of Arsenical Cobalt, in Chatham, in Connecti- 

 cut. 



It exists in a bed, in mica slate, varying in width from a 

 few inches to a few feet. The matrix is a mixture of horn- 

 blende and actynolite, in which the ore is disseminated. It 

 was explored several years since, and has been again open- 

 ed recenily; the undertaking is now, however, abandoned. 

 Arsenical sulphuret of iron, arsenical nickel, and arseniate 

 of cobalt are found in this mine in small quantities. 



Vol. VI.—No. II. 27 



