Dear Sir

I avail myself of the opportunity of the Satellite sailing tomorrow for the Pacifick, to thank you very sincerely for your obliging letter of the 5^th: of April, from East Falkland Island, which was brought to me by the Dublin a few days since, together with the very interesting specimens accompanying it. I had no idea that either those islands, or the coast of Patagonia, presented so much interest to a geologist, and you will have had the satisfaction of visiting regions entirely unknown to the rest of the world.— I will not fail to answer the queries contained in your letter, respecting the geology of Rio Grande, and other southern parts of Brazil which I examined, at least as far as my very limited knowledge of the subject permits of.— I have not time, however, to do so today.— Doctor Sellow, a Prussian naturalist, learned in all departments of natural history, passed I believe two years in exploring Rio Grande, and St. Pauls, and made extensive collections.¹ He died afterwards in the interior of Brazil, and I am ignorant whether he left any journal or account of his travels and observations. I heard frequently of him in that country, as also of M. Auguste St. Hilaire, a french traveller, but whose researches were confined to botany.² The Flora of the South of Brazil is little known, and extraordinarily beautiful, and as a far greater number of the plants would succeed in Europe, than of those collected in the tropical regions, it is a great pity that the Horticultural Society do not send out collectors,—and the more so, as the country is habitable and hospitable, and easy to travel about; indeed, the moment you pass from the oriental territory into the Brazilian, you emerge at once from a savage into a civilized region.— An English travelling naturalist, M^r: Andrew Matthews,³ but whose objects are chiefly, I believe, entomology, and botany, is about to undertake an adventurous journey, directly across this conti-nent, from Lima to Rio de Janeiro. I obtained passports and recommendations for him for this Government, and I wrote to Colonel Wilson⁴ at Lima, to urge him not to neglect, if possible, collecting some specimens of rocks in the course of his journey. He will most probably have left Peru before you arrive there. At St. Iago de Chili, you will of course become acquainted with M^r: Caldcleugh,⁵ who is residing there, whom you will find a very accomplished chemist and mineralogist, as well as a most agreable well informed and obliging person.— I hope you will continue your kindness, in sending me a few small fragments of the Andes, and of any of the islands that you visit.—

Our last political news from Europe bring word of the downfal, at last, of Dom Miguel, who, with his friend Don Carlos of Spain, embarked for England on the 30^th: of May.— We have this intelligence from Lisbon, as the English June Packet is not yet arrived. I suppose this letter will find the Beagle somewhere on the coast of Chili or Peru.

I remain, My Dear Sir, | your faithful and obedient servant | H. S. Fox