mmonites, they
have formed a marked feature in the geography of the globe. The geology
of these mountains pleased me in one respect; when reading Lyell, it had
always struck me that if the crust of the world goes on changing in a
circle, there ought to be somewhere found formations which, having the
age of the great European Secondary beds, should possess the structure
of Tertiary rocks or those formed amidst islands and in limited basins.
Now the alternations of lava and coarse sediment which form the upper
parts of the Andes, correspond exactly to what would accumulate under
such circumstances. In consequence of this, I can only very roughly
separate into three divisions the varying strata (perhaps 8,000 feet
thick) which compose these mountains. I am afraid you will tell me
to learn my ABC to know quartz from feldspar before I indulge in such
speculations. I lately got hold of a report on M. Dessalines D'Orbigny's
labours in S. America (7/2. "Voyage dans l'Amerique Meridionale, etc."
(A. Dessalines D'Orbigny).); I experienced rather a debasing degree of
vexation to find he has described the Geology of the Pampas, and that I
have had some hard riding for nothing, it was however gratifying that my
conclusions are the same, as far as I can collect, with his results. It
is also capital that the whole of Bolivia will be described. I hope to
be able to connect his geology of that country with mine of Chili.
After leaving Copiapo, we touched at Iquique. I visited but do not quite
understand the position of the nitrate of soda beds. Here in Peru, from
the state of anarchy, I can make no expedition.

I hear from home, that my brother is going to send me a box with books,
and a letter from you. It is very unfortunate that I cannot receive this
before we reach Sydney, even if it ever gets safely so far. I shall not
have another opportunity for many months of again writing to you. Will
you have the charity to send me one more letter (as soon as this reaches
you) directed to the C. of Good Hope. Your letters besides affording
me the greatest delight always give me a fresh stimulus for exertion.
Excuse this geological prosy letter, and farewell till you hear from me
at Sydney, and see me in the autumn of 1836.

LETTER 8. TO JOSIAH WEDGWOOD. [Shrewsbury, October 5th, 1836.]

My dear Uncle

The "Beagle" arrived at Falmouth on Sunday evening, and I reached home
late last night. My head is quite confused with so much delight, but