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Darwin Correspondence Project

From Trenham Reeks   25 February 1845

Museum of Economic Geology

25th. Feby. 1845.

Dear Sir,

I have much pleasure in enclosing you a copy of the analysis of the Salt (No 759.)1 I can find nothing in it to account for its inferiority and my former suspicion of its being Potassium proves groundless.

I am, Dear Sir | Your obedient Servt. | Trenham Reeks C Darwin Esqre. Analysis of Salt (No. 759) from Patagonia. Chloride of Sodium— 99.52 Sulphate of Lime 0.26 Earthy matter 0.22 —– 100.00 —–

CD annotations

Top of first page: ‘Tuff specimens’ pencil, del pencil; ‘Second d’Orbigny about value of Salt’2; ‘Not in Geology’ pencil


From a salt lake near the Rio Negro (see Journal of researches 2d ed., p. 66, and South America, p. 74, where the analysis is quoted).
A reference to Orbigny 1835–47, 2: 130, in which the mining of salt from the pans of Andres Pas is discussed.


Encloses analysis of salt from Patagonia. Cannot account for its inferiority.

Letter details

Letter no.
Trenham Reeks
Charles Robert Darwin
Sent from
Museum of Economic Geology
Source of text
DAR 39: 45–6
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 831,” accessed on 16 September 2019,

Also published in The Correspondence of Charles Darwin, vol. 3