226. In this class are arranged the leaves and stalks of such vegetables as are eaten at table in the form of "greens and salads." Some ancient nations, we are told, were accustomed to range over fields and woods in search of food, devouring, like animals, any wild herb they could find likely to satisfy their hunger:

"Quae sol atque imbres dederant, quod terra crearat Sponte sua, satis id placabat pectora donum".

Lucret. lib. v.

Some herbs are still eaten in a raw state; but they are far less digestible than when cooked. During the heats of summer they are refreshing, and are well calculated to assuage that febrile state which full meals of animal food are known to occasion. Of all these herbs, the Water-Cress is the most beneficial; for, by operating in some degree as an aromatic, it promotes digestion, and corrects that tendency to flatulency which other raw vegetables are apt to produce. According to Xeno-phon, the ancient Persians lived upon water-cresses, which they considered the most wholesome of vegetable productions1. The Lettuce is generally eaten with other herbs, in the form of a salad, dressed with oil and vinegar. Some difference of opinion has arisen with respect to the propriety of such additions. Gosse, of Geneva, found that vinegar retarded its solution in the stomach; and oil has been stated by others to render it less digestible. I have generally found such condiments useful, and that dressed lettuce is less likely to ferment in the stomach than that which is eaten without them. Oil is known to have such an effect in checking fermentation, and the vinegar is not found to promote it.

The lettuce contains a narcotic principle1; and the effect of this is, in a great measure, obviated by a vegetable acid. Those persons, therefore, who eat lettuce with a view to obtain such effects, ought to take it without vinegar. Whatever difference of opinion may exist with regard to lettuce, there is none with regard to celery, the digestibility of which is greatly increased by maceration in vinegar. Cucumbers are by far the most unwholesome of all raw vegetables, and should be avoided as poison by dyspeptics.

1 The island of St. Helena abounds with them, and I am informed that crews arriving there when suffering with scurvy, almost immediately experience relief from their use.

227. The vegetables which require to be boiled are the different species and varieties of coleivort; the value of which does not depend so much upon their nutritive quality as the tenderness of their texture. On this account, the cauliflower and brocoli are the species to be preferred, particularly the younger sprigs of the former. Of the kinds where the leaves only are employed, the Savoy is of a sweeter and more tender texture than the others, particularly its central and upper leaves. The Cabbage tribe appear to contain a peculiar essential oil, whence the unpleasant odour of cabbage water; this matter is liable to produce offensive effects on the stomach. The vegetable should therefore be boiled in two successive waters, in order to free it entirely from the noxious ingredient, and at the same time to render its texture soft and digestible. Asparagus is quickly dissolved in the stomach, and, when sufficiently boiled, is not disposed to create flatulence or acidity: along with its mucilage it frequently contains some sweetness, which affords a proof of its nutritive quality. From the peculiar odour which it imparts to the urine of those who eat it, it appears to possess some active matter distinct from its mucilage; and it is generally considered diuretic.

I have, however, prepared a strong infusion, as well as extract, from it, in order to ascertain this point, and I have not been able to discover any diuretic effects from its administration in large doses. Asparagus is only wholesome when in an intermediate state, between root and plant. When older than this, it is remarkably acrid.

1 We are told that Galen, in the decline of life, suffered much from morbid vigilance, until he had recourse to eating a lettuce every evening, which cured him.