PERSPIRABILITY. The sum of what can be said on this matter is this, that such foods as promote an accumulation of fluid in our vessels, and dispose to plethora, are the least perspirable, and commonly give most strength; that the more alkaline foods are the most perspirable, though the viscous and less alkaline may attain the same property by long retention in the system. The authors on perspirability have determined the perspiration of foods as imperfectly as Mr Geoffroy has done the solubility, and in a few cases only. We must not lay hold on what Sanctorius has said on the perspirability of mutton, because he has not examined in the same way other meats in their perfect state; far less on what Keil says of oysters, as he himself was a valetudinarian, and consequently an unfit subject for such experiments, and probably of a peculiar temperament.
As to the effects of Food on the MIND, we have already hinted at them above. It is plain, that delicacy of feeling, liveliness of imagination, quickness of apprehension, and acuteness of judgment, more frequently accompany a weak state of the body. True it is, indeed, that the same state is liable to timidity, fluctuation, and doubt; while the strong have that steadiness of judgment, and firmness of purpose, which are proper for the higher and more active scenes of life. The most valuable state of the mind, however, appears to reside in somewhat less firmness and vigour of body. Vegetable aliment, as never over-diluting the vessels or loading the system, never interrupts the stronger motions of the mind; while the heat, fulness, and weight, of animal food, are an enemy to its vigorous efforts. Temperance, then, does not so much consist in the quantity, for that always will be regulated by our appetite, as in the quality, viz. a large proportion of vegetable aliment.
A considerable change has now taken place in the
articles made use of as food by the ancients, by substituting, instead of what were then used, particularly of the vegetable kind, a number of more bland, agreeable, and nutritive juices. The acorns and nuts of the primitive times have given way to a variety of sweeter farinaceous seeds and roots. To the malvaceous tribe of plants so much used by the Greeks and Romans, hath succeeded the more grateful spinach; and to the blite, the garden orach. The rough borage is supplanted by the accecent forrel; and asparagus has banished a number of roots recorded by the Roman writers under the name of bulbs; but Linnaeus is of opinion, that the parsnip has undeservedly usurped the place of the skirret. The bean of the ancients, improperly so called, being the roots as well as other parts of the arvorea melambos, or Indian water-lily, is superseded by the kidney-bean. The garden rocket, eaten with and as an antidote against the chilling qualities of the lettuce, is banished by the more agreeable cress and tarragon; the apium by the meliorated celery; the pompion, and others of the cucurbitaceous tribe, by the melon; and the sumach berries, by the fragrant nutmeg. The silphium, or succus Cyrenaicus, which the Romans purchased from Persia and India at a great price, and is thought by some to have been the asafetida of the present time, is no longer used in preference to the alliaceous tribe.
To turn from the vegetable to some of the animal substitutes, we may mention the carp among fishes as having excluded a great number held in high estimation among the Romans. The change of oil for butter; of honey for sugar; of mulla, or liquors made of wine, water, and honey, for the wines of modern times; and that of the ancient zythus for the present improved malt liquors; not to mention also the callida of the Roman taverns, analogous to our tea and coffee.
Food of Plants. See AGRICULTURE, no 1—6. and PLANTS; also the article COMPOSTS.