Our Fellow Travellers Would Have Returned By The Shortest Way, That Of The Pimichin And The Small Rivers; But M. Bonpland Preferred, Like Me, Persisting In The Plan Of The Voyage, Which We Had Traced For Ourselves In Passing The Great Cataracts.

We had already travelled one hundred and eighty leagues in a boat from San Fernando de Apure to San Carlos, on the Rio Apure, the Orinoco, the Atabapo, the Temi, the Tuamini, and the Rio Negro.

In again entering the Orinoco by the Cassiquiare we had to navigate three hundred and twenty leagues, from San Carlos to Angostura. By this way we had to struggle against the currents during ten days; the rest was to be performed by going down the stream of the Orinoco. It would have been blamable to have suffered ourselves to be discouraged by the fear of a cloudy sky, and by the mosquitos of the Cassiquiare. Our Indian pilot, who had been recently at Mandavaca, promised us the sun, and those great stars that eat the clouds, as soon as we should have left the black waters of the Guaviare. We therefore carried out our first project of returning to San Fernando de Atabapo by the Cassiquiare; and, fortunately for our researches, the prediction of the Indian was verified. The white waters brought us by degrees a more serene sky, stars, mosquitos, and crocodiles.

We passed between the islands of Zaruma and Mini, or Mibita, covered with thick vegetation; and, after having ascended the rapids of the Piedra de Uinumane, we entered the Rio Cassiquiare at the distance of eight miles from the small fort of San Carlos. The Piedra, or granitic rock which forms the little cataract, attracted our attention on account of the numerous veins of quartz by which it is traversed. These veins are several inches broad, and their masses proved that their date and formation are very different. I saw distinctly that, wherever they crossed each other, the veins containing mica and black schorl traversed and drove out of their direction those which contained only white quartz and feldspar. According to the theory of Werner, the black veins were consequently of a more recent formation than the white. Being a disciple of the school of Freyberg, I could not but pause with satisfaction at the rock of Uinumane, to observe the same phenomena near the equator, which I had so often seen in the mountains of my own country. I confess that the theory which considers veins as clefts filled from above with various substances, pleases me somewhat less now than it did at that period; but these modes of intersection and driving aside, observed in the stony and metallic veins, do not the less merit the attention of travellers as being one of the most general and constant of geological phenomena. On the east of Javita, all along the Cassiquiare, and particularly in the mountains of Duida, the number of veins in the granite increases. These veins are full of holes and druses; and their frequency seems to indicate that the granite of these countries is not of very ancient formation.

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