In proceeding now to give such information as I have been able to collect respecting the state of the provinces on the road to Peru, and to the westward of it, I shall take them in their geographical order, although it may be as well to observe that they were not, as may be supposed, originally conquered and settled by the discoverers of the Rio de la Plata. Those adventurers, following the course of the river Paraguay, reduced to subjection the warlike tribes they found upon its shores, and, navigating its higher branches, after incredible hardships and many valiant deeds, succeeded in opening a communication with their countrymen in Peru; but they made no attempt to possess themselves of the vast extent of country lying to the westward of them. The discovery of those regions was reserved for the followers of Almagro, who, after the conquest of Peru, marched southward to take possession of Chile, in fulfilment of his agreement with Pizarro; and his successors laid claim to them as part of the jurisdiction originally allotted to him in virtue of that agreement--a pretension which gave rise to many contentions amongst the chiefs who first established themselves in those parts; nor were they put an end to until, by the king's authority, these settlements, comprising Tucuman, Santiago del Estero, the towns in the valley of Catamarca, and many others since destroyed, were erected into a distinct and separate province called Tucuman, from the chief of the Calchaqui tribes which inhabited them. This was in 1563, some years before the existence of Buenos Ayres. Nor was it indeed till nearly half a century after De Garay had founded his settlement there that they became politically connected, and were united under one and the same government. PROVINCE OF CORDOVA. The province of Cordova, after that of Buenos Ayres, is the most important of the Union. According to a census taken in 1822-23, the population then amounted to something more than 85,000 souls, of which from 12,000 to 14,000 lived in the city. It is ruled by a governor, who is elective by a provincial junta occasionally convoked, and whose power is almost arbitrary; he has the command of all the forces and militia of the province, and has the power of reversing, on appeal, all decisions of the tribunals.