Page:De re metallica (1912).djvu/107

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BOOK III.
65

In the next place, venae profundae differ not a little in the manner in which they intersect, since one may cross through a second transversely, or one may cross another one obliquely as if cutting it in two.

If a vein which cuts through another principal one obliquely be the harder of the two, it penetrates right through it, just as a wedge of beech or iron can be driven through soft wood by means of a tool. If it be softer, the principal vein either drags the soft one with it for a distance of three feet, or perhaps one, two, three, or several fathoms, or else throws it forward along the principal vein; but this latter happens very rarely. But that the vein which cuts the principal one is the same vein on both sides, is shown by its having the same character in its foot walls and hanging walls.

Sometimes venae profundae join one with another, and from two or more outcropping veins[1] , one is formed; or from two which do not outcrop one is made, if they are not far distant from each other, and the one dips into the other, or if each dips toward the other, and they thus join when they have descended in depth. In exactly the same way, out of three or more veins, one may be formed in depth.

  1. Crudariis. Pliny (xxxiii., 31). says:— "Argenti vena in summo reperta crudaria appellatur," "Silver veins discovered at the surface are called crudaria." The German translator of Agricola uses the term sylber gang—silver vein, obviously misunderstanding the author’s meaning.