The people of Gaul, and of Aquitania[216] more particularly, make use of panic; the same is the case, too, in Italy beyond the Padus, with the addition, however, of the bean, without which they prepare none of their food. There is no aliment held in higher esteem than panic by the nations of Pontus. The other summer grains thrive better in well-watered soils than in rainy localities; but water is by no means beneficial to millet or panic when they are coming into blade. It is recommended not to sow them among vines or fruit-trees, as it is generally thought that these crops impoverish the soil. CHAP. 26. (11)—THE VARIOUS KINDS OF LEAVEN. Millet is more particularly employed for making leaven; and if kneaded with must,[217] it will keep a whole year. The same is done, too, with the fine wheat-bran of the best quality; it is kneaded with white must three days old, and then dried in the sun, after which it is made into small cakes. When required for making bread, these cakes are first soaked in water, and then boiled with the finest spelt flour, after which the whole is mixed up with the meal; and it is generally thought that this is the best method of making bread. The Greeks have established a rule that for a modius of meal eight ounces of leaven is enough. These kinds of leaven, however, can only be made at the time of vintage, but there is another leaven which may be prepared with barley and water, at any time it may happen to be required. It is first made up into cakes of two pounds in weight, and these are then baked upon a hot hearth, or else in an earthen dish upon hot ashes and charcoal, being left till they turn of a reddish brown. When this is done, the cakes are shut close in vessels, until they turn quite sour: when wanted for leaven, they are steeped in water first. When barley bread used to be made, it was leavened with the meal of the fitch,[218] or else the chicheling vetch,[219] the proportion being, two pounds of leaven to two modii and a half of barley meal. At the present day, however, the leaven is prepared from the meal that is used for making the bread. For this purpose, some of the meal is kneaded before adding the salt, and is then boiled to the consistency of porridge, and left till it begins to turn sour. In most cases, however, they do not warm it at all, but only make use of a little of the dough that has been kept from the day before. It is very evident that the principle which causes the dough to rise is of an acid nature, and it is equally evident that those persons who are dieted upon fermented bread are stronger[220] in body. Among the ancients, too, it was generally thought that the heavier wheat is, the more wholesome it is. CHAP. 27.—THE METHOD OF MAKING BREAD: ORIGIN OF THE ART.