of the Southern part of Essex County. 91 



Lynn, Middleton and Topsfield. From the latter place great 

 numbers of bowlders are carried into the north western part of 

 Danvers. In all these instances the feldspar is of a red color. 



CLASS IV. METALS. 



The southern section of Essex County is very destitute of 

 metals, no metallic bed having yet been discovered ; all there- 

 fore known of the metallic substances is to be found in diffused 

 state. 



GENUS IV. COPPER. 



Pyritous copper is found in small masses and grains, diffused 

 through the trap and slate rocks of Nahant. 



GENUS V. IRON. 



Species 1. Sulphur et of Iron (Pyrites), is diffused through 

 the trap rocks in many places at Nahant, Lynn, and Saugus, 



Species 2. Specular oxide of Iron, occurs forming a drusy 

 coating upon the rocks, at the south part of Little Nahant. 



Species 3. Argillaceous oxide of Iron, (Bog-ore) occurs in 

 Saugus, near the Newburyport turnpike. 



GENUS VI. LEAD, 



Species 1 . Sulphuret of Lead, ( Galena) a few particles have 

 been found in the prase of Nahant, and in a vein of carbonate ot 

 lime, near Phillips* beach, Lynn. 



GENUS VII. MANGANESE. 



Species 1. Oxide of Manganese, occurs in beautiful dendrites 

 in the crevices of brecciated porphyry, in Lynn, a few rods north 

 of the establishment for the manufacture of India rubber loth, 

 and at Lover's Leap. 



But the most splendid dendrites of this oxide, occur in a ledge 

 of porphyry and compact feldspar, at Wood End, Lynn, in the 

 track of the Eastern Rail Road ; while blasting for that road in 

 1838, vast quantities of the fragments of the rocks thrown out, 

 exhibited upon their surface a most fanciful and splendid display 

 of dendrites. 



