1889. ] NEW YORK ACADEMY OF SCIENCES. 145 
line quartz. This variety of rock has been found to be richer 
in cassiterite than those which carry less mica and more nearly 
approach quartz or feldspar in composition. 
My intention this evening was merely to deliver an informal 
talk upon this subject, to show the veins of tin-ore and the re- 
gion in which it is found, and to give a few crude ideas on the 
subject that may lead to further investigation by those who are 
more capable and more familiar with geology and mineralogy 
than myself. 
Respecting map No. 1, I would remark that we have not the 
true course of the tin formation; the curve was rendered neces- 
sary by the unfortunate way of putting places on the maps. 
This formation runs nearly due northeast and southwest until 
~ it crosses the granite, and then it turns due north and south 
until the granite region is passed, when it takes again nearly 
the northeast and southwest course, which continues to be the 
trend as far as I have examined it. 
The Richmond and Danville Railroad, after leaving Danville, 
crosses this micaceous formation with the identical trap leads, 
the greisen rock, ete., though the greisen differs somewhat in 
appearance from that near King’s Mountain, the mica appearing 
to be more on the order of muscovite, and the feldspar looks 
dryer, though the general appearance of the rock is similar. 
This formation crosses the railroad between Danville and Lynch- 
burg, commencing about thirteen miles from Franklin Station 
and extending three miles north of it, in a width, as the rail- 
road runs, of about sixteen miles, embracing the King’s Moun- 
tain formation, precisely the same rock, accompanied by the 
mica slates, etc. Whether the limestone occurs there or not, I 
am not now informed. 
Respecting the trap dikes, my observations have led me to 
conclude that they are identical with those of New Jersey and 
belong to the same period. 
DISCUSSION. 
Dr. ALBERT R. Lepoux.—I think that the first thing neces- 
sary to say is something that our friend Mr. Furman touched 
upon so very lightly that it may not perhaps have been noticed. 
This is, that to Mr. FurMAN himself belongs the credit, not only 
of the discussion, not only of the examination of this deposit, 
but we may say of the discovery of it; because, although it is 
true that a school-boy some years ago picked up a piece of cas- 
siterite, Mr, FURMAN was the first to discover the tin in the 
