Account of the four-month voyage to Tierra del Fuego, Cape Horn, and return. The Fuegians are landed with Richard Matthews [the missionary in charge of them]. Storms, seasickness, hostile savages, and scenery are described. His increasing interest in all branches of natural history makes the hardships worth while. FitzRoy buys a schooner. CD will stay at Rio Negro while it is fitted.

With the help of General Rosas, CD has just finished an overland journey from Patagones to Buenos Aires; he tells of fossil finds at Bahia Blanca and Guardia del Monte. Spring reminds him of home.

Describes his trip to north of Santa Fé, his illness, and return by boat to Buenos Aires – which he found in the throes of a revolution. Covington is cut off from the town, which some expect to be plundered.

His troubles during the revolution have ended well.

Now plans to investigate geological formations at Rio Negro. Is concerned about the expense but cannot bear to miss seeing "one of the most curious pieces of Geology".