This section is from the book "Meals Medicinal", by W. T. Fernie. Also available from Amazon: Meals Medicinal: With "Herbal Simples" Curative Foods From the Cook in Place of Drugs From the Chemist.
Anyhow, vegetables should be cooked only in their own juices, or at least in as little water as possible; most of the valuable salts will otherwise be assuredly washed out, and sacrificed. When deluged with water in boiling the substance of vegetables retains only as much food value as boiled shavings would possess; and it is this worthless mass which must be then eaten, and its digestion attempted. It will in the case of Cabbage stay inert within the stomach and bowels, for five or six hours, giving rise to flatulence, distension, and discomfort. If the Cabbage were eaten without being cooked at all, it would be digested in less than three hours. For obtaining the maximum of benefit from cooked roots, and green vegetables, they should always be steamed over boiling water, and not boiled out of all their goodness.
Vegetables, and milk served together are likely to disagree, because the milk (which when taken by itself becomes quickly digested) is then retained in admixture with the more slowly-digesting vegetable food, and undergoes fermentation, with sour products. Milk, and meat, are likewise a bad combination for the same reason; milk alone is chiefly digested beyond the stomach in the small intestine, which it speedily reaches. Some salt should be put with vegetables when they are boiled; and a very little butter, if added just before they are served, gives improved flavour. The length of time for cooking them should be twice, sometimes three times as long as is generally allowed in this country. All green vegetables should be boiled in an open saucepan, and should be put on in a little boiling water to be cooked (unless special reasons can be given for the contrary); roots are to be boiled with the saucepan lid kept on, the preservation of a good colour being in either case the object in view. Purees of vegetables, with meat, are of great value for the sick, likewise to persons in health but with defective teeth, or soreness affecting the membranes of mouth, and throat; also as part of the diet of growing children.
A puree is, as the name denotes, essentially a purifying process as to foods, whereby the edible parts are separated, and removed from the rough, hard, inedible parts by the mechanism of sifting. Thus from leguminous pods the indigestible shells are removed; from roots, and leaves, the stringy cellulose is separated. Tough meat, old fowls, and the remains of cold poultry can be turned to good account in a puree.
Onions, and Cabbages, were not grown in England to any extent until Queen Elizabeth's time, when they began to be cultivated widely, together with Carrots, and Parsnips, throughout Suffolk, and at Fulham. It was half a century later before "Colle-flowers" became generally known; and at this period Turnips were never used in cookery, but were always boiled, and eaten separately with butter. Radishes were grown, also Beans, and Peas; likewise Melons, and Pumpkins. By the very poor a coarse kind of bread was made with Peas, and Acorns. The Medical Magazine teaches that nowadays raw market vegetables should be washed, and then soaked for at least half an hour in a weak solution of tartaric acid, which is a cheap, and powerful antiseptic, of quite a harmless character.
From the time of Pythagoras, the doctrine and practice of an entirely vegetable diet has been enjoined by many advocates, the same mode of living having been pursued for ages by numerous Hindus, and Buddhists. As to this food system known as vegetarianism, or living exclusively on vegetable sustenance, the question, to begin with, does not lie in the problem (as many persons argue) whether we are structurally, and physiologically constituted as herbivorous, or as carnivorous beings, for it is perfectly certain we are neither. Carnivorous animals feed on flesh alone, and eat that flesh raw, but nobody proposes that we should imitate them in this practice. Again, the herbivorous creatures eat raw grass, but nobody is rash enough to suggest that we should follow their example. From which source, then, can we best obtain the nutritive constituents of our main food supplies? We may not by any means suppose that merely because the chemical constituents of vegetables are equal in nutritive value to the corresponding constituents of animal food, that therefore as a whole, vegetable nourishment can replace meat, or that, vice versa, meat can altogether be substituted for vegetable diet.
The form in which the nutritive ingredients are presented to the digestive organs materially affects their utility as foods. "A glass of whisky," as Dr. Hutchison forcibly argues, "is chemically the same whether it be taken neat, or diluted with a tumblerful of water; but the effects on the body are radically different." Moreover, man stands apart from all other creatures as a cooking animal; his teeth are not constructed for munching, and grinding, hard, raw grain; nor are his digestive organs naturally adapted for assimilating grain in such a condition, even if it were reduced to pulp by mastication at first. Vegetarianism has much to be said in its favour for persons of adequate digestive capabilities; but certain objections must be raised against its adoption unreservedly when the digestive powers are feeble, and the measure of food at meals limited of necessity by personal incapacities.
There are fundamental principles connected with the system in question which closely underlie the main issue. One of these is embodied in the important fact that the cell walls which enclose the proteids, or nitrogenous nourishment, consist in vegetables of cellulose, a tough membrane which makes the extraction of such proteids more difficult from within the cells than it is from animal flesh; and this cellulose is characterized by an extraordinary insolubility. "The vegetarian question," writes Dr. E. Hutchison, "is really a question of nitrogen, and of that alone, which can be obtained in a concentrated form only from animal sources. Moreover, energy is not to be confused with muscular strength. A grass-fed carthorse is strong; a corn-fed hunter is energetic. Such energy is a property of the nervous system; strength is an endowment of the muscles, and these are chiefly nourished by the carbohydrates which vegetables can supply; but the brain needs nitrogenous proteids." Dr. Kuttner, of Berlin, having made an impartial investigation into the respective merits of vegetarianism, and mixed diet, has come to the conclusion that a mixed diet, including meat, is most suitable for man, because exclusive, vegetable nourishment is too bulky, promoting discomforts of digestion, and being assimilable only to a certain extent; moreover, animal stuffs engender fuller bodily warmth.