Some precautions were taken (see Cod. Theod. 1. xi. tit. ii. and Cod. Justinian. 1. x. tit. xxvii. leg. 1, 2, 3) to restrain the magistrates from the abuse of their authority, either in the exaction or in the purchase of corn: but those who had learning enough to read the orations of Cicero against Verres (iii. de Frumento) might instruct themselves in all the various arts of oppression, with regard to the weight, the price, the quality, and the carriage. The avarice of an unlettered governor would supply the ignorance of precept or precedent.