The waters of the Pilcomayo are, for the most part, extremely foul. The Rio Salado derives its origin from the mountains of Salta. In sundry places it changes both its channel and its name. At first it is called Rio Arias, presently Rio Passage, and afterwards, in the neighbourhood of the castle de Val Buena, Rio Salado. Beyond the city of Santa Fè, it assumes the name of Coronda, and finally, under this name, loses itself in the mighty waters of the Parana. For a length of way, its waters are not only sweet, but very famous for their salubrity, which, however, tributary lakes and rivers corrupt with such filth and saltness, that, for the space of many leagues, the very beasts refuse to touch it. It may be worth while to notice the origin of its saltness. The neighbouring plains abound in the shrub _vidriera_, the ashes of which reduced to a calx are employed in the making of glass. The _vidriera_ resembles the juniper; the berries are small and cylindrical, green, nearly transparent, and joined one with another, being in place both of boughs and leaves. If I remember rightly, it bears no fruit. The rain falling upon these shrubs, contracts a saltness, and flowing down the country, communicates it to the lakes and streams, which enter rivers sweet at their source, and miserably taint them. The palm tree (_carandaỹ_) under which salt-petre is produced, has the same effect as the _vidriera_. But though the waters of the Rio Salado be salt, they are pellucid, and in the deepest parts the excellent fish, with which this river abounds, are perceptible at the bottom. Its channel is deep, and contained within narrow, though lofty and precipitous banks, through which it quietly flows, unnavigable, except near Santa Fè. Between the Salado and Dulce flows the rivulet Turugon, which, being girt with woods, even in the driest weather, affords plentiful and sweet waters to the traveller, as it is neither interrupted by shallows, nor tainted with salt. It is not far distant from the little Indian town Salabina. The Rio Dulce, which is the Nile of the territory of St. Iago, after proceeding a little southerly, overflows its banks, and is finally received by the lake of gourds (Laguna de los Porrongos) between Cordoba and Santa Fè. Not many leagues distant is the white lake, (Laguna Blanca,) where the Indians and Spaniards affirm that howlings, as of bulls, are heard in the dead of the night.