On Metallic Minerals. 399 



with the different acids and alkalis, whiclj, decomposing 

 animal and vegetable subi^tances afford becomes capable 

 of dissolving oxidulous iron, &.c. When such Maters 

 become stagnant a precipitation ensues not only of those 

 minerals, &c. which may have been held in mechanical 

 suspention by the water, but also of most of those which 

 are chemically combined with it. In this manner an 

 argillaceous and phosphorized variety of iron ore is formed 

 of a thickness proportioned to the time this reproducing 

 power has been in action. Indicative of this natural process 

 the interior of the cells of bog ore are sometimes lined with 

 a blue phosphate of iron. In the south western parts of 

 New Jersey, where bog ore occurs in great abundance, 

 many spots previously exhausted are explored again 

 successfully, after the lapse of about twenty years. 



The iron is probably derived from the ferruginous sand 

 banks which have been said to characterize this place, and 

 from deposits of magnetic iron in the primary chain to the 

 northward, the existence of which the profusion of mag- 

 netic sand which the waters of the St. Maurice throw upon 

 it? shores, renders almost certain. 



It is worthy of remark that the ore Is here said to be 

 deposited on a coarse while sand and never on clay. Tlie 

 thin stratum of clay, which it would ajipear was necessary 

 to retain the waters, holding the iron in solution sufliciently 

 long ill a stagnant slate to allow of its precipitation, {.a 

 purpose coarse sand would scarcely ans\\er,) has perhaps 

 been converted into bog ore by a j^pecies of inijiregnalion 

 common to this substance, and often decidedly observed in 

 roots of trees, &c., as it is probable that a similar formation 

 has seldom been deposited originally on any other than a 

 retentive sub soil. 



3 K 



