mulli: and then all rock fish. [AX] αὐτόπυρον. And there is not only a difference in the classes of things, but also in the things themselves; which arises from their age, the different parts of their body, the soil, air, and the case they are in. For every four footed animal(42), that is sucking, affords less nourishment; also a dunghill fowl, the younger it is. In fish too, the middle age, before they have reached their greatest bulk. _For the parts_, the heels, cheeks, ears, and brain of a hog; of a lamb or kid, the whole head with the petty toes, are a good deal lighter than the other parts; so that they may be ranked in the middle class. In birds, the necks or wings are properly numbered with the weakest. As to the soil, the corn, that grows upon hilly parts, is stronger than what grows upon a plain. Fish got in the midst of rocks, is lighter than those in the sand; those in the sand, than those in the mud. Whence it happens, that the same kinds either from a pond, or lake, or river, are heavier: and that, which lives in the deep, is lighter than one in shoal water. Every wild animal also is lighter than a tame one: and whatever is produced in a moist air, than another in a dry. In the next place, all the same foods afford more nourishment, fat than lean; fresh more than salt; new than stale. Again, the same thing nourishes more, when it is stewed into broth, than roasted, more roasted than fried. A hard egg is of the strongest kind; soft, or sorbile(43) of the weakest. And though all grains, made into bread, are most firm, yet some kinds washed, as alica(44), rice, ptisan, or gruel made of the same, or pulse(45), and bread moistened with water, may be reckoned with the weakest. With regard to drinks, whatever is prepared from grain, also milk, mulse, defrutum, passum(46), wine either sweet or strong, or must, or very old wine, are of the strongest kind. But vinegar, and wine a few years old, or austere, or oily, is of the middle kind. And therefore none of these should be given to weak people. Water is weakest of all. And the drink, that is made of grain, is stronger in proportion to the hardness of the grain itself: and that wine, which is produced in a good soil, more so than in a poor soil; or in a temperate air, than one, which is either over moist or too dry, and either over cold or too hot. Mulse, the more honey it contains, defrutum, the more it is evaporated in boiling, and passum, the drier the grape is from which it is prepared, are so much the stronger. Rain water is lightest; next spring water, then river water, then that of a well; after these snow, or ice; water of lakes is heavier than these; and that of fens heaviest of all. The trial is both easy and necessary to those, that want to know its nature. For the lightness appears from weighing it; and amongst those, that are of equal weight, the sooner any of them grows hot or cold, and the more quickly herbs are boiled in it, the better it is.