Feb, I, 1886,] THE TROPICAL AGRICULTURIST. 



5^7 



PLUMBAGO USED AS A MORTAR AND 

 AS A DYE IN CHINA. 

 Recently we have been able to collect a great 

 deal of information regiiiding graphite in its various 

 forms and the muUitiidiuous uses to which it is 

 applied, and now we have a very curious con- 

 tribution to our knowledge fi'om China. It will 

 be seen that, by tlie celestials, a special form of 

 graphite, associated with coal and bitumen, but 

 confounded with neither by the astute Chinese, is 

 used when mechanically united to lime as a plaster or 

 mortar and with cloth fibres (also mechanically), so as 

 to form a permanent dye. Here are two new uses for 

 the extraordinary substance which aids in the manu- 

 facture of steel ordnance, is itself manufactured 



into pencils, and is good as a lubricant and a 

 fire-proof paint. It was formerly valued as a 

 medicine, and the WTiter of the very interesting 

 aciount we quote has found the form of the ore 

 lie describes useful in surgery as a stjiJtic and 

 a substitute for substances usually employed as 

 ■• dry dressings." 



NOTES ON THE SO-CALLED "BLACK 

 LI.AIE " OF CHINA. 



The following note on Black Lime, by Dr. A. P. 

 Peak, Tientsin, appears in the Customs Medical 

 Reports : — 



This substance is made by Dr. Williams to be " a 

 kind of bitumen," and as it has not been mentioned 

 by any other WTiter with whose pages I am familiar, 

 possibly the correction of this mistake and the 

 noting of two uses to which it is put by -the Chinese 

 may prove of interest. 



A suspicion of its bituminous origin might arise 

 from the facts that at some places tliere are found 

 traces of petroleum in coimexion with the coal 

 measures near which it is found, and that water in 

 which it is macerated sometimes shows an iridescent 

 film upon its surface. The substance in question is, 

 however, atiionihot's gruiihite ; and although it is 

 mined in localities near the coal beds, the Chinese 

 themselves insist that it has no connexion with 

 them. The provinces of Chihli and Shantmig are 

 mainly supplied from mines in the foot hills of the 

 range boundin" the great plain on the north-west, 

 and much of tliis material is shipped from Liuli-ho, 

 whence large quantities of lime and coal are also 

 forwarded, this citv, situated at the head of one of 

 the affluents of the Peiho, being the distributing 

 point for a large mountain reigion. Near Liu-li-ho 

 surface indications of petroleum seem to abound. 



One of the uses before mentioned is its mixture 

 with lime, to make a very hard and durable plaster, 

 used in situations that are exposed to the weather. 

 iieeause of this association, the Chinese call this 

 " lime " like the other, although, as they say, it has 

 not the fiery principle of the white lime. 



A peculiarity of this graphite is its avidity for 

 water, not from chemical afhuity, as with lime, but 

 from its great absorbent qualities. The crude graph- 

 ite, in lumps as it comes from the mines, when 

 exposed lo contract with water, at once becomes 

 permeated by it, and falls into powder. In this 

 state the particles slide upon each other with the 

 greatest ease, giving that lubricating quality which 

 fs chractcristic of graphite. When mixed with 

 freshly slake! lime, gr.'i.plnte in this state can be 

 very thoroughly iiicorpor;ited with it, each one of 

 the finely divided particles becoming imbedded lu 

 a matrix of lime, and liy laborious working and 

 pressure, as the mortar -^ets the m.asa can be so 

 consolidated as to make, when hardened, one of the 

 best and finest grained mortara known, speciraonB 



of which can be seen in the so-called "chnnam" 

 roofs. 



The superiority of this mortar is due solely to 

 the physical character of the little knife-edged, 

 microscopic fragments of carbon : and j'et, strange 

 to s.ay, the use of silicious sand iu mortar does 

 not seem to have commended itself to native build- 

 ers. I have never been able to get one who was 

 not familiar with foreign ways of building to 

 acknowledge its utility. True, . is somewhat difhr- 

 ult to obtain on this great alluvial plain : still, 

 where it can be had, so far as I know, loam Is 

 nsed in preference. 



To pass to the second economic use of graphite ; 

 this is the curious one of dyeing cloth. The cotton 

 garments universally worn by the middle clas.'ies are 

 coloured with thi.s substance. The cloth is soaked in a 

 hot, a<|ueous mixture of graphite, in which there is a 

 little glue; it is then placed on a stone and mauled 

 with wooden beaters ; again imnier.st^d and again 

 beaten, the process being repeated many times with 

 each piece, until the cloth assumes a deep and uni- 

 form tint attaiued by thus mechanically forcing the 

 fine particles of carbon more and more deeply into the 

 fibre of the cloth. 



I have r.irely seen a more beautiful object than 

 fibres .-craped from the cloth, loaded with brilliant, 

 razor-like fragments of carbon, like diamond dust, 

 especially whin viewed in glycerine, under a ^ immer- 

 sion h.:i. It is difficult to believe that such beautiful 

 transparent objects make up in mass the dull opaque 

 plumbago. 



This ])rocess of dyeing, if we may call it so, I believe 

 to be unique in tlie art as practis d at the present day. 

 The colour is, of course, indestructilile by the sun ur 

 chemical action, and can only be dischai-ged by thorough 

 and repeated washings. Hence it makes a very satis- 

 factory and permanent colour for Obinese garments, 

 aud approves itself to the utilitarian native mind, as 

 witness its universal u-^e. 



Graphite is abundant, and sells in the market here for 

 5 cash a catty ; yet these are all the industrial uses of 

 it, so far as I know. 



Lead pencils, crucibles, stove blacking and lubricat- 

 ing are uot yet achieved by means 0*' it. 



Oddly enough, the Chinese have not thought of using 

 it in medicine. Yet the great hygroscopic qualities 

 of the fine, soft, velvety powder, which may easily he 

 obtained by levigation, in<licate a direction iu which it 

 may advautageouslv be employed. 



In such affections as require dry dressings, e. g., 

 moist eczemas anil purulent otitis, it could not fail to 

 be of service. As a styptic it is of considerable value, 



1 have found that a couibiuation of 3 pirts of graphite, 



2 pHrts of. resin, and 1 part of acacia, by weight care- 

 fully triturated, possesses very marked haemostatic 

 properties. — Hongkong Daily Press, 12tb Jan. 



SPINEL-BEARING DOLOMITE. 

 Much of our crystallized mountain limestone, 

 which occurs in beds amongst our other primitive 

 rocks is so full of iron pyrites that by many it 

 is believed that this source of sulphur would supply 

 a local manufactory of sulj^huric acid. Occasion- 

 ally our dolomite exists with the gold-like iron 

 pyrites replaced by sapphire-blue crystals of spiuol. 

 But this latter form is so rare that during our 

 long residence in Ceylon we had not seen it until 

 about three weeks ago Mr. A. J. Kellow brought 

 us some very beautiful specimens from his estate. 

 New Cornwall, in the Ambawella or New Gahvay 

 Valley, below Nuwara Eliya. He told us he had 

 for many years been in the habit of burning the 

 ordinary form of the rock into lime, but that it 

 was only recently that the breaking-up of a fresh 

 bed had revealed the 'blue crystals. A large and 

 very beautiful sapphire-like crystal which Mr. Kellow 

 showed us as having been found in the rock ought 

 to have dissipated the idea o£ copper pyrites which 



