In Search of the Castaways by Jules Verne — Read

The native troop engaged by Glenarvan consisted of three men and a boy. The leader of the muleteers was an Englishman who had lived in the country for twenty years. His occupation was to let mules to travelers, and guide them across the passes of the Andes. Then he consigned them to the care of a laqueano (Argentine guide), who was familiar with the road over the Pampas.

This Englishman had not so forgotten his native tongue, in the company of mules and Indians, that he could not converse with the travelers. Hence it was easy for Glenarvan to make known his wishes, and for the muleteer to execute his orders, of which circumstance the former availed himself, since Paganel had not yet succeeded in making himself understood.