This nutritive operation hath four other subordinate functions or powers belonging to it—attraction, retention, digestion, expulsion. _Attraction_.] [980]Attraction is a ministering faculty, which, as a loadstone doth iron, draws meat into the stomach, or as a lamp doth oil; and this attractive power is very necessary in plants, which suck up moisture by the root, as, another mouth, into the sap, as a like stomach. _Retention_.] Retention keeps it, being attracted unto the stomach, until such time it be concocted; for if it should pass away straight, the body could not be nourished. _Digestion_.] Digestion is performed by natural heat; for as the flame of a torch consumes oil, wax, tallow, so doth it alter and digest the nutritive matter. Indigestion is opposite unto it, for want of natural heat. Of this digestion there be three differences—maturation, elixation, assation. _Maturation_.] Maturation is especially observed in the fruits of trees; which are then said to be ripe, when the seeds are fit to be sown again. Crudity is opposed to it, which gluttons, epicures, and idle persons are most subject unto, that use no exercise to stir natural heat, or else choke it, as too much wood puts out a fire. _Elixation_.] Elixation is the seething of meat in the stomach, by the said natural heat, as meat is boiled in a pot; to which corruption or putrefaction is opposite. _Assation_.] Assation is a concoction of the inward moisture by heat; his opposite is semiustulation. _Order of Concoction fourfold_.] Besides these three several operations of digestion, there is a fourfold order of concoction:—mastication, or chewing in the mouth; chilification of this so chewed meat in the stomach; the third is in the liver, to turn this chylus into blood, called sanguification; the last is assimilation, which is in every part. _Expulsion_.] Expulsion is a power of nutrition, by which it expels all superfluous excrements, and relics of meat and drink, by the guts, bladder, pores; as by purging, vomiting, spitting, sweating, urine, hairs, nails, &c. _Augmentation_.] As this nutritive faculty serves to nourish the body, so doth the augmenting faculty (the second operation or power of the vegetal faculty) to the increasing of it in quantity, according to all dimensions, long, broad, thick, and to make it grow till it come to his due proportion and perfect shape; which hath his period of augmentation, as of consumption; and that most certain, as the poet observes:— Stat sua cuique dies, breve et irreparabile tempus Omnibus est vitae.——— A term of life is set to every man, Which is but short, and pass it no one can.