No. 31.— 1885.] 



PLUMBAGO. 



189 



the abundance of wood fuel, The old Dutch Goveroor's notice 

 of plumbago is so curious that it may be well to reproduce 

 its terms. The translation from Valentyn is as follows 



" Of the other minerals found in the hill-country there is little to 

 be said, for want of information ; but we ourselves have found both 

 black lead [potloot~] and common lead ; from which metallurgists, 

 infer that there must also be quicksilver there, of which black 

 lead is the product. It is also believed that in the low-country, 

 where the black lead is found, large mines will be discovered 

 so that it seems necessary to inquire into this further, with a 

 view to quicksilver, as this is as it were the blood of minerals 

 and a sign of richer mineral."-— Vol. V., p. 205. 



Changes the most extraordinary are now known to be 

 produced by metamorphic agencies, but I suspect that even 

 the most potent forces at work in nature would be powerless 

 to change mercury into black lead. Modern mineralogical 

 science, too, scarcely recognizes the principle that quicksilver 

 is the blood of minerals, and its occurrence an indication of 

 the existence of still more precious minerals. The possible 

 solution of the anthracite mystery may be that although 

 graphite is no more a carburet of iron, as it was once 

 deemed, than it is a darker form of the common metal lead, 

 yet iron in very anomalous forms is sometimes associated 

 with plumbago. I was once in possession of a bit of iron 

 formation found in a plumbago mine, which so closely 

 resembled the rootlet of a plant, that the probability seems 

 to be that particles of iron ore in the soil had aggregated 

 round a tree root, assuming its shape and taking its place, 

 after a fashion which gold and other metals have frequently 

 adopted. When rock thus takes the place of wood, we call 

 the result a petrifaction. In the case of metallic particles, 

 the process may be regarded as a form of natural electro- 

 plating, a process in the arts for the success of which the use 

 of good conducting graphite (for some is said to be non- 

 conducting) is essential. There is, it may be well to say, 

 a metallic graphite produced in iron furnaces, known to the 

 workmen as "kish," but it differs somewhat from natural 

 plumbago, which is all and always immediately of vegetable 

 origin, whether the vegetation has passed directly into 

 graphite or through the intermediate stages of coal or shale. 



But to return to the place in history of our subject. A 



d2 



