B. A. ROBERTS&J. PROCTOR The term 'serpentine' referring to rocks and min of each of the polymorphs. These conditions in erals, can be traced back to the ancient Roman clude temperatures of generally less than 530 C, era of Dioscorides (A. D. 50) (Faust & Fahey and fluid pH's in excess of 10 with low pC02 Serpentine protoliths are essentially ultramafic 1962) and they suggest that the speckled colour of serpents and the fact that Dioscorides recom rocks which fall into a number of categories: (a) mended it for the prevention of snakebite as two stratiform complexes, (b) concentrically zoned...