1. In the last chapter, I distinguished granulated rocks from composite rocks, of which the most important to the general reader are of course those in which one of the component substances may be sometimes separable in the form of a gem. Of these, one of the most interesting masses in the world is the mountain with the pretty name, Adula, which rises in the midst of the St. Gothard Pass, above the plain, I believe, on which the old Hospice still stands. In the substance of that single mountain are found, in confused crystals, some fifteen or twenty (I will count presently) different minerals, all of them interesting, and five precious; namely, first, the one which takes its name from the mountain, Adularia—in the finest conditions of it, used by jewellers under the name of moonstone; secondly, the red garnet, which is the subject of our immediate inquiry; thirdly, the most beautiful rock-crystal that can be found in the world; fourthly, the jewel described by Saussure under the name of Sappare, as blue as a pale sapphire, and much brighter than any sapphire, if left in its natural crystal; and, lastly, the mineral called, I know not why, but very prettily, Tourmaline, sounding as if it were the Tower of Mechlin, and indeed forming towers, when perfectly crystallized, which uninformed fairies might take for the Tower of Giotto built of ruby.