Chap. 32.] CHALCANTKUM, OR SHOEMAKEIIS' BLACK. 201 



Across these reservoirs there are a number of immovable 

 beams, to which cords are fastened, and then sunk into the water 

 beneath by means of stones ; upon which, a slimy sediment 

 attaches itself to the cords, in drops of a vitreous^^ appearance, 

 somewhat resembling a bunch of grapes. Upon being removed, 

 it is dried for thirty days. It is of an azure colour, and of a 

 brilliant lustre, and is often taken for glass. "When dissolved, 

 it forms the black dye that is used for colouring leather. 



Chalcanthum is also prepared in various other ways : the 

 earth which contains it being sometimes excavated into 

 trenches, from the sides of which globules exude, which 

 become concrete when exposed to the action of the winter 

 frosts. This kind is called " stalagmia,"'^ and there is none 

 more pure. When its colour is nearly white, with a slight 

 tinge of violet, it is called **lonchoton."*^ It is also prepared 

 in pans hollowed out in the rocks ; the rain water carrying the 

 slime into them, where it settles and becomes hardened. It is 

 also formed in the same way in which we prepare salt ;^" the 

 intense heat of the sun separating the fresh water from it. 

 Hence it is that some distinguish two kinds of chalcanthum, 

 the fossil and the artificial ; the latter being paler than the 

 former, and as much inferior to it in quality as it is in 

 colour. 



The chalcitis which comes from Cyprus is the most highly 

 esteemed for the purposes of medicine, being taken in doses of 

 one drachma with honey, as an expellent of intestinal worms. 

 Diluted and injected into the nostrils, it acts detergently 

 upon the brain, and, taken with honey or with hydromel, it 

 acts as a purgative upon the stomach. It removes granula- 

 tions upon the eye-lids, and is good for pains and films upon 

 the eyes ; it is curative also of ulcerations of the mouth. It 

 arrests bleeding at the nostrils, and hsemorrhoidal discharges. 

 In combination wdth seed of hyoscyamus, it brings away 

 splinters of broken bones. Applied to the forehead with a 

 sponge, it acts as a check upon defluxions of the eyes. Made 

 up into plasters, it is very efficacious as a detergent for sores 



2" From this vitreous appearance of the crystals of vitriol, it is most pro- 

 bable that vitriol derives its name. See Beckmann, Vol. I. p. 184. 



:» "Drop," or " globule" chalcanthum. 



-3 Possibly a corruption of " leucoion," " violet white." 



30 He has described the mode of procuring salt, by evaporating the 

 brine in shallow pits, in B. xxxi. c. 39.— B. 



