1889. ] NEW YORK ACADEMY OF SCIENCES. 147 
here, and which is true of the North Carolina deposits, applies 
equally well to the tin deposits of Australia, where the greisen 
is like this; and it is true also that these Australian deposits, 
where they have been worked with comparatively little success 
in the veins, have yielded profit in the gravels. 
Mr. FuRMAN has given no figures ; and although I have made 
many analyses both of small samples and of samples weighing as 
much as fifty tons, yet,as one would naturally expect, in any deposit 
where the material sought for is scattered all through the rock, 
very little result can be reached by assays, so I am not prepared 
to present any figures that would give anything like an average 
of these veins. On the one hand, there are bodies that have been 
exposed, perhaps a number of tons of mineral, that would yield 
up to five or six per cent of tin, but nothing like an average of 
such richness ; and if one should estimate it at less than one 
per cent, he would probably be nearer the truth. 
But, on the other hand, in that whole region, from King’s 
Mountain several miles north and five or six miles south, wher- 
ever there is a stream, we find more or less stream-tin, and as 
we get down to the large creek which runs between the tin 
formation and the King’s Mountain range proper, even there 
we find it. The question as to whether or not there has been 
sufficient surface decomposition of. the rocks to render the 
stream-tin a paying enterprise, is a very important one. As 
I understand it, itis not believed that glacial action extended 
as far south as the Carolinas; and this being the case, the kind 
of erosion or decomposition is only that incidental to atmos- 
pheric action. 
Now, in all the slates further northeast, in the gold-bearing 
sections, and from what one can see here in the railroad cuts, 
the soft soil extends very deep, and one can go down with a pick 
and shovel as far as sixty or seventy feet before reaching rock 
hard enough to blast; and where a railroad cut goes through, 
owing to the great variations of the winter temperature,—almost 
daily freezing and thawing,—the rock is very quickly decom- 
posed; so that naturally, unless there were some abnormal condi- 
tions present, I would expect to find that these deposits had not 
been eroded there, but simply decomposed by the agencies of frost, 
