49 SYDNEY H. BALL: 
mass. Т. L. Watson found it a constituent of the following basic rocks 
of Nelson Co. Virginia, gabbro, nelsonite and diabase and also in syenite. 
Кемь reports small amounts of carbon in the Adirondack gabbros and 
titaniferous iron ores and Harwoon from 0.22 to 0.04 % carbon in 
the Ventersdorp diabase. 
As a constituent of pegmatites and to a less extent of pes- 
matitic Sranites. 
Graphite is a minor constituent of many of the quartz-felspar- 
pegmatites, usually garnetiferous, which are associated with the flake- 
graphite-bearing granite-gneiss. Graphite-bearing pegmatites also occur 
with the Lange graphite. Graphite in scales up to one inch across, 
occurs more abundantly in the borders of dikes. Microscopic exam- 
‚ ination shows that the solidification of graphite doubtless to a small 
degree preceded that of quartz and felspar (largely orthoclase, some 
sodie plagioclase), but for the most part graphite is younger than them, 
and in part even replaced them. Graphite is reported to be a constituent 
of the pegmatite of the sodalite syenite pegmatites of South Greenland. 
Graphite masses of presumably pesgmatitic origin. 
The graphite of Langø (Long Island) was early known to the 
Eskimos, and prior to 1845 they showed specimens to English whalers: 
In 1845 two brigs and two schooners visited the island and got samples. 
An Englishman, Davipson or Davison, in the same year sunk five 
shallow pits on the northwestern portion of Langø from which some 
100 tons of graphite were mined. Dr. SUTHERLAND, who was at Uper- 
nivik in 1850 says “plumbago of tolerable purity is rather abundant. 
I believe the whalers were the first to discover it and to bring some 
to Britain. It was found of considerable value in the market and might 
have been the source of profit to persons who sent out ships for cargoes 
of it had not the directors (of the Greenland trade, S.H.B.) and the 
Danish government sent out orders to their representatives in Green- 
land to prohibit all British ships taking any of it away”. The quantity 
is, however, not as great as one might infer from Dr. SUTHERLAND’S 
remarks, and all of the known deposits are believed to be comparatively 
small lenses. 
The country rock is pegmatite containing, in addition to much 
garnet, a few cordierite particles. In it are a few almost completely 
absorbed inclusions of granite gneiss. Graphite occurs as vertical or 
nearly vertical lenses, with irregular offshoots, which have maximum 
widths of 1.5m (5 feet) and lengths of 15m (fifty feet) (See Fig. 17). 
Graphite also occurs as a film upon the fractures of the pegmatites. 
