Concerning the gold itself, there seem to have been various means employed for manufacturing substitutes for the genuine article. A curious recipe is given in the manuscript of Jehan de Begue, "Take bulls' brains, put them in a marble vase, and leave them for three weeks, when you will find gold making worms. Preserve them carefully." More quaint and superstitious is Theophilus' recipe for making Spanish Gold; but, as this is not quotable in polite pages, the reader must refer to the original treatise if he cares to trace its manufacture. Brushes made of hair are recommended by the Brussels manuscript, with a plea for "pencils of fishes' hairs for softening." If this does not refer to _sealskin_, it is food for conjecture! And for the binding of these beautiful volumes, how was the leather obtained? This is one way in which business and sport could be combined in the monastery, Warton says, "About the year 790, Charlemagne granted an unlimited right of hunting to the Abbot and monks of Sithiu, for making... of the skins of the deer they killed... covers for their books." There is no doubt that it had occurred to artists to experiment upon human skin, and perhaps the fact that this was an unsatisfactory texture is the chief reason why no books were made of it. A French commentator observes: "The skin of a man is nothing compared with the skin of a sheep.... Sheep is good for writing on both sides, but the skin of a dead man is just about as profitable as his bones,--better bury him, skin and bones together." There was some difficulty in obtaining manuscripts to copy. The Breviary was usually enclosed in a cage; rich parishioners were bribed by many masses and prayers, to bequeath manuscripts to churches. In old Paris, the Parchment Makers were a guild of much importance. Often they combined their trade with tavern keeping, in the twelfth and thirteenth centuries. The Rector of the University was glad when this occurred, for the inn keeper and parchment maker was under his control, both being obliged to reside in the Pays Latin. Bishops were known to exhort the parchment makers, from the pulpit, to be honest and conscientious in preparing skins. A bookseller, too, was solemnly made to swear "faithfully to receive, take care of, and expose for sale the works which should be entrusted to him." He might not buy them for himself until they had been for sale a full month "at the disposition of the Masters and Scholars." But in return for these restrictions, the bookseller was admitted to the rights and privileges of the University. As clients of the University, these trades, which were associated with book making, joined in the "solemn processions" of those times; booksellers, binders, parchment makers, and illuminators, all marched together on these occasions. They were obliged to pay toll to the Rector for these privileges; the recipe for ink was a carefully guarded secret.