No. 31.— 1885.] 



PLUMBAGO. 



187 



But in the process of my researches I find that it is not 

 only the ancient Sinhalese wedaralas who prescribed graphite. 

 The English black lead, it seems, was formerly held in high 

 repute as a medicine, and a writer on the Cumberland plum- 

 bago in 1 709 asserted it was much sought after by physicians 

 and apothecaries as being a present remedy for colic, gravel, 

 and other diseases. The use of euphorbia juice in the 

 purifying process applied in Ceylon to plumbago is very 

 curious and interesting, the powerfully active properties 

 of euphorbia "milk" being well-known. The Tamil coolies 

 are said to give doses of euphorbia juice to new-born 

 infants for the alleged purpose of clearing away impurities, 

 but the result is probably to account in a large measure for 

 the high rate of infant mortality amongst the class referred 

 to. Any one who knows, as the writer does, the agony arising 

 from a single drop of euphorbia "milk" getting into the eye, 

 will appreciate the effect of this caustic poison on the delicate 

 internal organs of infants. On the external skin it acts as 

 a blister. Its action on graphite is probably to dissolve 

 away the impurities mixed with the mineral in the shape of 

 particles of gneiss, quartz, iron, &c. Having seen it stated 

 that in connection with specimens of plumbago at the 

 Exhibition of 1862, the eminent surgeon, Sir Benjamin 

 Brodie, had fully discussed the properties of the mineral, I 

 requested Dr. Vanderstraaten to ascertain if Brodie's views 

 were embodied in any book in the Medical Library ; he has 

 replied in the negative, but tells me that the Chinese use 

 both black lead and white as medicines. 



The species of carbon of which we are treating never forms 

 a compound with any other substances, and large masses of 

 it are often found so pure that the return of carbon to the 

 analyst is sometimes considerably above 99 — very nearly 100 

 per cent, indeed, while the specific gravity of the soft and 

 unctuous mineral compares with that of the diamond thus : 

 diamond 3-6 ; graphite 2*2. The fact may not be wanting 

 in significance, that quartz occasionally encloses drops of 

 liquid carbon, destined perhaps to emerge, after a very long 

 period of intense heat and pressure, as solid gems. (?) 



In cases of impaired digestion, purified carbon, in the shape 

 of graphite, may well be conceived to have valuable corrective 

 effects, but native treatment is generally so empirical that 



