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which I had observed in the gneiss- granite of 

 Caraccas and the Oroonoko, in the hornblende 

 slates of Angostura, and even in the greater part 

 of the secondary rocks we had just examined. 

 The beds, on a vast extent of land, make the 

 same angle with the meridian of the place ; they 

 present a parallelism (or rather a loxodromism) , 

 which may be considered as one of the great 

 geognostic laws susceptible of being verified by 

 precise measures. In advancing toward cape 

 Chuparuparu, the size of the veins of quartz^ 

 that cross the micaslate, increased. We found 

 some that were from one to two toises broad, 

 full of small fasciculated crystals of rutile-titan- 

 ite. We sought in vain for cyanite, which we 

 had discovered in some blocks near Maniquarez, 

 Farther on, the micaslate furnishes not veins, but 

 little beds of graphite or carburetted iron. They 

 are from two to three inches thick, and have 

 precisely the same direction and inclination as 

 the rock. Graphite, in primitive soils, marks 

 the first appearance of carbon on the globe, that 

 of carbon uncombined with hydrogen. It is 

 anterior to the period when the surface of the 

 earth became covered with monocotyledonons 

 plants. We enjoyed from the height of those 

 wild mountains a majestic view of the island 

 of Margaretta. Two groups of mountains, which 

 we have already mentioned, those of Macanao, 

 and la Vega de San Juan, rise from the bosom 



