remarked, 1 that probably some beds of serpentine were originally hornblende rock, or diorite. This has since been fully established; while serpentine it self, on the other hand, can be transmuted into chlorite and talcose schist. The presence of serpen tine almost exclusively amongst that class of rocks known as metamorphic, is, amongst other pheno mena, in favour of the more modern view. B. von Cotta even questions whether serpentine exists as an original and independent mineral, as the crystals with amorphous fracture, which some mineralogists call serpentine, according to others are only pseudo- morphs of crysolite, or some other mineral. 2 Bischof and G. Bose also share this view, and have shewn that serpentine may originate by alteration from the most diverse rocks and minerals. 3 M. Delesse has shewn that the variations of colour in serpentine are in a great measure due to the proportion and degree of oxidization of the iron which it contains ; 4 a deduction which may be illustrated by a comparison of the analyses of the deep red varieties from the Lizard in Cornwall with those of some other districts of a generally greenish hue. The following will serve for examples of the chemical composition of this rock. 1 Neues Jahrb. p. 283. 2 Yon Cotta, Rocks, Eng. ver. 314. 3 Chron. and Phys. Geol., Eng. ver. ii. 417. 4 Zirkel, Petrog. i. 320.