With regard to the two prevailing Indian languages spoken in the
southern part of the continent, it is remarkable that the Quichua, the
language of the Peruvians, is still used by the natives found on the
banks of the River Salado, in the province of Santiago del Estero,
though far-distant from the Andes, in the centre of the Argentine
territory; while it is not in use in the intermediate provinces. This
proves, either the distance to which the Incas extended their conquests,
or perhaps the fact that the natives of Santiago are descendants of a
Peruvian colony. The Guarani language is still spoken in Entre Rios and
Corrientes, while in the Republic of Paraguay it is more generally used
than the Spanish; indeed, paragraphs printed in it appear in one of the
papers published in that province. The Jesuits compiled a number of
grammatical and other works in the Guarani, for the purpose of teaching
the novitiates in their establishments at Paraguay.
The Guarani nation occupied the whole sea-coast, from Uruguay northwards
through Brazil, Cayenne, and even into Venezuela.