BOOK XXXIV. XXXI. I22-XXXII. 125 



tions. The method is to boil 16 drams of it in a 

 twelfth of a pint of vinegar with honey added till it 

 becomes of a viscous consistency : this makes a 

 useful preparation for the purposes above mentioned. 

 When it is necessary to make it softer, honey is 

 sprinkled on it. It also removes the callosity of 

 fistulous ulcers when the patients use it with vinegar 

 as a fomentation ; and it is used as an ingredient in 

 eye-salves, arrests haemorrhage and creeping or 

 putrid ulcers, and reduces fleshy excrescences. It 

 is particularly useful for troubles in the sexual 

 organs in the male, and it checks menstruation. 



XXXII. The Greeks by their name for shoe- shoemakers 

 makers'-black " have m.ade out an affinity between ^''^*' 

 it and copper : they call it chalcanthon, ' flower of 

 copper ' ; and there is no substance that has an 

 equally remarkable nature. It occurs in Spain in 

 wells or pools that contain that sort of water.* 

 This water is boiled with an equal quantity of pure 

 water and poured into wooden tanks. Over these 

 are firmly fixed cross-beams from which hang cords 

 held taut by stones, and the mud clinging to the 

 cords in a cluster of glassy drops has somewhat the 

 appearance of a bunch of grapes. It is taken off and 

 then left for thirty days to dry. Its colour is an 

 extremely brilliant bhie, and it is often taken for 

 glass ; when dissolved it makes a black dye used for 

 colouring leather. It is also made in several other 

 ways : earth of the kind indicated is hollowed into 

 trenches, droppings from the sides of which form 

 icicles in a winter frost which are called drop-flower 

 of copper, and this is the purest kind. But some of 

 it, violet with a touch of white, is called lonchoton, 

 ' lance-headed.''^ It is also made in pans hollowed 



219 



