127 



taken from Professor BOXXKY'S paper. At Bulhammie Hill, near Colmonell, 

 a serpentine containing brilliant crystals of bronzite (bastite ?) in a black 

 groundmass occurs. The rock is identical in appearance with the black 

 serpentine near Cadgwith, Cornwall, and appears to have been originally 

 composed of olivine and enstatite. The conspicuous porphyritic crystals have 

 been analysed by Dr. HEDDLE (see ante p. 118), and the black groundmass, 

 deprived of the crystals, by Mr. HOUGHTOX. Mr. HOUGHTOX'S analysis is as 

 follows : 



Si0 2 ... ... ... ... 38-29 



A1 2 0, ... ... ... ... 3-95 



Fe.O, ... ... ... ... 2-53 



FeO ... ... ... ... 4-04 



CaO ... ... ... ... 0-57 



MgO ... ... ... ... 35-55 



MnO ... ... ... ... tr. 



NiO ... ... ... ... 0-15 



FeS 2 ... ... ... ... tr 



H 2 14-08 



99-16 



Along the coast by Lendalfoot serpentine is seen in association with 

 the so-called " dioritic " rocks. These latter, in the few cases investigated 

 by Professor BOXXKY, contain augite and not hornblende. They are in part 

 massive and in part schistose. They represent, as it were, the hornblende 

 schists of Cornwall, and are in all probability massive igneous rocks which 

 have been more or less affected by regional metamorphism. The junctions 

 between the serpentine and these latter rocks are sharp and irregular, and 

 " tongues of the serpentine penetrate the diorite." The serpentine about 

 Lendalfoot has a "rather conchoidal fracture with a very compact dark olive 

 green groundmass, containing rather minute and not very lustrous bronzitic 

 crystals and thin veins of chrysotile." Picotite is present. 



A dull red serpentine with bastite occurs to the south of Carletou foot. 

 A greenish serpentine mottled with white steatite occurs near the stone 

 marking five miles from Ballantrae. North of Lendalfoot saussuritic gabbro 

 and massive diallage rock occur in association with serpentine. The gabbro, 

 like that of Cornwall, contains saussurite, a little unaltered plagioclase, 

 diallage, uralite and actiuolite. 



Other Scotch Serpentine Localities. One of the best known of 

 these is Portsoy in Banffshire. Here, as elsewhere, the rock occurs in 

 relation with gabbro and plagioclase - hornblende rocks (diorite). Dr. 

 HEDDLE ^' to whom we are indebted for a description of the mineralogical 



(1) Trans. Koyal Sue. Edinburgh, Vol. XXVLLL, 1879, p. 514. 



