No. 129.] 207 



Although these facts have long been known to those living in 

 that section of country, yet the probable cause of this unusual 

 fertility have only recently been explained. It appears to be 

 owing to the cropping out of a vein of plumbago or plumbagin- 

 ous feldspar tJiroughout the whole extent of the fertile tract by 

 the gradual disintegration and decomposition of which the soil 

 has been formed. This soil is quite light and easy of tillage, and 

 when moist, is of a deep black color. It will in many places 

 produce, without the application of manure, crops fully equal if 

 not supeilor to those raised on manured land only a short distance 

 beyond the limits of the vein, and possesses the power of with- 

 standing, in a remarkable degree, the exhausting effect of long 

 continued and heavy cropping, receiving in the meanwhile only 

 scanty supplies of manure. When applied in any considerable 

 quantities, manures are found to act with great energy, seemingly 

 stimulating vegetation to an unusual degree. 



These phenomena, occurring as they do only at isolated points, 

 and only in connection with the outcrops of this and similar veins 

 of plumbago and feldspar, are manifestly owing to some pecu- 

 liarity in this soil derived from the subacent materials. The 

 veins in which the mingled minerals occur are of varied extent 

 and richness, and the included plumbago generally of the granu- 

 lar variety. Often the entire vein is composed of nearly pure 

 plumbago, with only a few nodules of the feldspar disseminated 

 throughout; in other cases the feldspar predominates and some- 

 times'almost entirely displaces the plumbago. The proper posi- 

 tion of these veins is among the primary rocks in Morris county, 

 generally in granite and gneiss. Although they may occur among 

 the newer formations, their lineof directiun is from the northeast 

 to the southwest, and their extent is from a few inches to nearly 

 a mile in width. 



This peculiar combination of plumbago and feldspar is found 

 to decompose very readily under the influence of the various 

 atmospheric agencies. This readiness to decompose seems to be 

 owing more to the feldspar than to the plumbago, as it is observed 

 that where there is little or no feldspar present, there the action 

 of frost, rain and other aids to decomposition has been produc- 



