Cinnabaris[1016] is adulterated by the agency of goats’ blood, or of bruised sorb-apples. The price of genuine cinnabaris is fifty sesterces per pound. CHAP. 40.—THE VARIOUS KINDS OF MINIUM. THE USE MADE OF IT IN PAINTING. According to Juba minium is also a production of Carmania,[1017] and Timagenes says that it is found in Æthiopia. But from neither of those regions is it imported to Rome, nor, indeed, from hardly any other quarter but Spain; that of most note coming from Sisapo,[1018] a territory of Bætica, the mine of minium there forming a part of the revenues of the Roman people. Indeed there is nothing guarded with a more constant circumspection; for it is not allowable to reduce and refine the ore upon the spot, it being brought to Rome in a crude state and under seal, to the amount of about two thousand pounds per annum. At Rome, the process of washing is performed, and, in the sale of it, the price is regulated by statute; it not being allowed to exceed[1019] seventy sesterces per pound. There are numerous ways, however, of adulterating it, a source of considerable plunder to the company.[1020] For there is, in fact, another kind[1021] of minium, found in most silver-mines as well as lead-mines, and prepared by the calcination of certain stones that are found mixed with the metallic vein—not the minerals, however, to the fluid humours of which we have given[1022] the name of quicksilver; for if those are subjected to the action of fire they will yield silver—but another kind of stone[1023] that is found with them. These barren[1024] stones, too, may be recognized by their uniform leaden colour, and it is only when in the furnace that they turn red. After being duly calcined they are pulverized, and thus form a minium of second-rate quality, known to but very few, and far inferior to the produce of the native sand that we have mentioned.[1025] It is with this substance, then, as also with syricum, that the genuine minium is adulterated in the manufactories of the company. How syricum is prepared we shall describe in the appropriate place.[1026] One motive, however, for giving an under-coat of syricum to minium, is the evident saving of expense that results therefrom. Minium, too, in another way affords a very convenient opportunity to painters for pilfering, by washing their brushes,[1027] filled with the colouring matter, every now and then. The minium of course falls to the bottom, and is thus so much gained by the thief.