Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 2 by Alexander von Humboldt
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page 27 of 644 (04%)
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of Valencia, and the whole system of small rivers flowing into it,
have no large alligators, though this dangerous animal abounds a few leagues off in the streams which flow either into the Apure or the Orinoco, or immediately into the Caribbean Sea between Porto Cabello and La Guayra. In the islands that rise like bastions in the midst of the waters, and wherever the rocky bottom of the lake is visible, I recognised a uniform direction in the strata of gneiss. This direction is nearly that of the chains of mountains on the north and south of the lake. In the hills of Cabo Blanco there are found among the gneiss, angular masses of opaque quartz, slightly translucid on the edges, and varying from grey to deep black. This quartz passes sometimes into hornstein, and sometimes into kieselschiefer (schistose jasper). I do not think it constitutes a vein. The waters of the lake* decompose the gneiss by erosion in a very extraordinary manner. (* The water of the lake is not salt, as is asserted at Caracas. It may be drunk without being filtered. On evaporation it leaves a very small residuum of carbonate of lime, and perhaps a little nitrate of potash. It is surprising that an inland lake should not be richer in alkaline and earthy salts, acquired from the neighbouring soils. I have found parts of it porous, almost cellular, and split in the form of cauliflowers, fixed on gneiss perfectly compact. Perhaps the action ceases with the movement of the waves, and the alternate contact of air and water. The island of Chamberg is remarkable for its height. It is a rock of gneiss, with two summits in the form of a saddle, and raised two hundred feet above the surface of the water. The slope of this rock is barren, and affords only nourishment for a few plants of clusia with large white flowers. But the view of the lake and of the richly |
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