W. JL. Foote — Native Lead at Franklin Furnace., N . J. 187 



the texture and composition of the tinguaite render the sepa- 

 ration of the analcite for analysis a practical impossibility, so 

 that its presence cannot be definitely proved as in the case of 

 Lindgren's analcite-basalts and the monchiquites. But the 

 chemical analysis of the rock, and the physical properties 

 previously mentioned, leave little doubt on this point. In 

 support of its primary character we must fall back upon the 

 freshness of the rock and the general arguments advanced by 

 Pirsson and Lindgren. 



It would seem necessary therefore to recognize the occur- 

 rence of analcite as a constituent of the tinguaites by the use of 

 the name analcite-tinguaite, and to this subgroup the tinguaites 

 of Manchester, Umptek, Crazy Mountains and possibly Hot 

 Springs and other localities belong. 



Locust, N. J., June 29, 1898. 



Art. XVIII. — Note on the Occurrence of Native Lead with 

 Roeblingite, Native Copper, and other minerals at Frank- 

 lin Furnace, N. J.; by Warren M. Foote. 



Mining done some months ago in the Parker shaft, North 

 Mine Hill, Franklin Furnace, N. J., at a depth of 800 feet, 

 yielded along with the usual ores occasional traces of native 

 copper.* With it occur a number of minerals including 

 roeblingite ;f this species is found rarely in white masses in 

 a grey porcellanous substance ; again, in balls or radial aggre- 

 gations of minute prismatic crystals, their terminations present- 

 ing a velvet surface ; also in brown and reddish masses. 



From different sources were secured specimens coming from 

 this vein. In examining them with a lens, I noted a dull and 

 discolored substance occurring in thin flakes. Its lead color 

 and high luster on a fresh surface, with its unusual sectility, 

 softness and malleability, at once suggested native lead. A 

 small piece was tested on charcoal. In the oxidizing flame it 

 easily volatilized, and a yellow coating was deposited, which 

 disappeared under the reducing flame. A grain of the metal 

 was quickly dissolved in hot dilute nitric acid. 



Four specimens were secured, and further search and inquiry 

 proved the metal to have occurred most sparingly. In one the 

 lead is found in exceedingly thin scales or Alms, filling the 

 crevices of the earthy porcellanous mineral, which broke so 

 that flat surfaces of the lead were exposed; with it is inti- 



* J. E. Wolff, Proc. of the Am. Acad, of Arts and Sciences, vol. xxxiii, No. 23. 

 f This Jour., vol. hi, p. 413, S. L. Penfield. 



