No. 31,-1885.] PLUMBAGO. 



253 



Appendix No. 3.0. 



Graphite, Mica, and Asbestos, and the absence of Fossils from 



the Metamorphic Rocks of Ceylon 

 are thus discussed by Dr. William King, of the G-eological 

 Survey of India, in reply to queries preferred by me when asked 

 to write a Paper on Graphite : — 



" Our knowledge of the organic origin of graphite is as yet 



little better than speculation I fancy graphite expresses 



a greater amount of metamorphism than anthracite We 



have one of the finest specimens, almost, in the world of museums 

 in our museum at Calcutta, which my brother -ZElian sent up. 



It is difficult to tell you why there are no fossils in your 



metamorphic rocks : there may have been very little life at the 

 time of their formation and that of the lowest forms, and these 

 may have been obliterated by metamorphism, or so altered that 

 nothing but the result of their chemical decomposition now 

 remains — e. g., this graphite. I do not think age would have 

 anything to do with the obliteration of vegetable structure, if it 

 ever existed ; metamorphism (which includes a tremendous lot of 



forces, chemical and otherwise) is quite sufficient, ....I do 



not think there is any relation between graphite, mica, and 

 asbestos — except in this way, that mica, being the common mineral 

 in mica schist, and mica schist being an altered form of veinic 

 shales, it is reasonable to suppose that seams of vegetable matter 

 might have been associated with those shales. For instance, it 

 is conceivable that shales with vegetable matter in layers will, by 

 pressure and in time, become carbonaceous shales and coal : 

 while intense metamorphism might bring about a further change 

 into mica schist and graphite— graphite which exists in granite 

 venis ; and mica in that case is the constituent of the granite, 

 the graphite being an accidental mineral. Asbestos is a form of 

 the magnesian rocks, so common in some gneiss regions ; it has 

 nothing to do with the graphite. 



" Very possibly the forms of vegetable life were more minute 

 than those of coal : but they may have existed in immense 

 numbers." 



Dr. King's opinion is of course decisive as to the absence of 

 mineral affinity between the two substances which of all others 

 best resist fire, and which common quality led me to put the 

 question. But associated with our gneiss rocks are beds of that 

 very magnesian limestone of which asbestos is stated by Dr. King 

 to be a form. As regards mica, the Sinhalese describe graphite as 

 its black form, {i Kalu-miniran," and one can scarcely wonder, for 



h 2 



