The bakers of Rome received from the public granaries whatever they required, at a price fixed by the magistrate. If the officer charged with the distribution of it gave a bad quality, or exacted a bribe to supply good corn, that officer was disgraced, and he became forever a journeyman baker.[IV-53] Independently of public bakeries, the number of which reached 329 under the reign of Augustus, there were also, in the houses of the wealthy, slaves whose sole occupation was the making of bread, and these slaves brought an exorbitant price when they excelled in their art.[IV-54] They used portable ovens, made of iron or earthenware, under which they placed red-hot coals. Sometimes they employed a round brass vessel with a cover, which was put under the flames. In the houses where the greatest luxury reigned, they had a kind of silver mould, from which the bread was taken, and served to the guests.[IV-55] It is absolutely necessary to dive into the private life of the Roman people, and not to neglect any of their domestic customs (accounts of which are scattered here and there, in the writings of the more serious historians, and among the dangerous frivolities of certain poets), if we wish to have a correct idea of the excessive refinement which the opulent classes evinced, even in the most ordinary things. Modern nations are satisfied with the bread more or less white, and even bear, without much complaint, certain illicit mixtures, in which various heterogeneous substances are sometimes strangely amalgamated; but this was not the case in Rome. The prefect of provisions (_præfectus annonæ_) was scrupulously careful to see that the supply of bread was abundant; that it was of exact weight; that the manipulation of it was excellent; and that it was made of the best flour the public granaries contained. As we have already observed, that was one of the most serious cares of the government on behalf of a people who only required two things--bread and the circus,[IV-56] and whose ferocity, when pressed by hunger, knew no bounds.[IV-57] They studied carefully every modification that the art of baking might seem to require: they examined the leaven in use, and experimented with new kinds. The following are the compositions Pliny has transmitted to us:-- The Romans thought much of millet for their leaven; they mixed it with sweet wine, in which they let it ferment a year. They employed, also, wheat bran, soaked for three days in sweet white wine, and dried in the sun. Of this they diluted a certain quantity at the time of making bread, which was left to ferment in the best wheat flour, and afterwards mixed with the entire mass. The leavens just mentioned were made during the vintage; the rest of the year they were replaced by the following:--A dish containing two pounds of barley paste was placed on red-hot coals, and heated until ebulition commenced. It was put into vessels till it became sour.