
          Albany, Aug 20th 1820. EVening

Dear friend,

Why did I not find a letter in the
post-office yesterday on my return from the Heldeberg[Helderberg]? 
Why have you not sent me Smith's
likeness? I shall stay and tomorrow night.
After that I shall be in Albany at least
every night [crossed out: ?] this week and next. We
have examined all the distant towns.

I send you some native sulphate of
magnesia. Will you send one specimen immediately
to Col Gibbs. Any quantity of it may
be obtained [crossed out: seventeen] [added:sixteen] miles from Albany.
in the east face of the most perpendicular
part of the Heldeburg[Helderberg]. I discovered it last
Wednesday while examining this mountain or hill.
Its geological position is at the meeting of the
Compact limestone and Secondary sandstone.
Here is a layer of sulphuret of iron in view about
5 rods in extent. It passes under the debris of the
mountain; but I presume it extends to a great
distance.

I send you something too, which I found in
Rutland Pond, Vermont. Is it Conferva diaphara?
It reatins its original appearance excepting
that it is translucent or nearly transparent
when first gathered. This mass I found near
the turnpike in Parkerstown on the highest
ridge at that place in the Green Mountains of
Vermont. What is it?

You give the locality of the hydrate of
alumine wrong. It is Richmond, Mass. in an
iron mine not wrought, of the Stalactitic hematite.
        