Tierra del Fuego and the barren coasts of Patagonia are "singularly unfavourable to the insect world". In the tropics, however, CD captured minute Coleoptera by the hundreds – which should result in his bringing home many undescribed species.

Is sending a cargo of specimens – birds’ skins, small quadrupeds, and fossil bones.

Describes his overland trip from Rio Negro to Buenos Aires and his expedition to Santa Fé.

Asks for mineralogical works to help him with the volcanic rocks of the west coast.

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".