Spons' Household Manual A treasury of domestic receipts and a guide for home management

Part 104

Chapter 1042,652 wordsPublic domain

A considerable proportion of our food, especially the fatty and starchy matters, after being digested and assimilated and stored up in the various tissues, is slowly burnt or oxidised by the oxygen which has been carried from the lungs by the blood; the fat is decomposed into carbonic acid and water, which are given off by the lungs and the kidneys and skin. By this oxidation, or burning, heat and force are generated to keep up the temperature of the body and keep the vital functions going, and to supply physical and mental energy, all the internal and external work of the body being performed by the combustion of the stored-up fat in the tissue. Hence the necessity of a regular and constant supply of food to warm the body, supply mental and physical energy, and repair the waste of the tissues. This brings us naturally to consider next whether this twofold function of food is performed by the same or any article of food. In some cases it is; but as most articles of food do not contain the substance required in suitable proportion to perform both these functions, we require to take more than one article of food to make up what the other lacks, and in this way we get a diet sufficient to fulfil both these functions. It is for this reason that articles of food, or their nutritive principle, have been classified according as they contribute especially to the growth and nutrition of the body, or to the production of heat and force, into two great classes:--(_a_) Heat-producers; (_b_) Flesh-formers, or non-nitrogenised and nitrogenised compounds.

(_a_) _Heat-producing, or Non-nitrogenised._ Sugar } { Carbon Starch } composed of { Hydrogen Gum } { Oxygen Oils and Fats }

(_b_) _Flesh-forming, or Nitrogenised._ { Carbon Albumen } { Hydrogen Gluten } { Nitrogen Fibrin } composed of { Oxygen Casein } { Sulphur and Legumin } { Phosphorus

Of these compounds those which contain nitrogen are used principally for building up the muscles, while those which contain no nitrogen are burnt up in the body to yield heat and force. The flesh-forming compounds are not obtained solely from animal food, as gluten and legumin are derived from the vegetable kingdom, from cereals and peas and beans respectively; while the heat-producers, with the exception of some oils and fats, are obtained solely from the vegetable kingdom. So that for perfect health our food must contain sufficient of both these two classes of compounds to repair the tissues, and to supply heat and force (the mineral substances being contained in these compounds, also partly supplied by the water we drink). As to the relative proportion in which they should be present in our food, there is no hard and fast line; this would be an impossibility unless we were to weigh and analyse every article we eat. We judge by experience what will satisfy the appetite and enable us to feel up to our work. Besides, it must vary considerably according to circumstances,--1st, the amount of work or exercise; 2nd, the climate. Thus physical or bodily exercise compels us to eat more than when idle, our increased hunger or appetite being nature’s method of indicating to our minds that our bodies require food to replace what has been expended in force and to repair the waste of the tissues. Then the colder the climate more food is required, especially of the heat-giving varieties, as more will be spent in keeping up the warmth of the body. Cold is also more conducive to physical work than warm weather, so that for this reason also more food is required in a cold climate.

The following table by Dr. Stevenson Macadam gives an idea of the relative amount of flesh-formers and heat-producers in certain articles of food, showing the amount of heat-producing elements they contain for every 10 parts of flesh-formers.

+----------------+---------------+----------------+ | | Flesh-forming.| Heat-producing.| |----------------+---------------+----------------+ | Rice | 10 | 123 | | Potatoes | 10 | 115 | | Barley | 10 | 57 | | Oatmeal | 10 | 50 | | Wheaten Flour | 10 | 44 | | Milk | 10 | 40 | | Fat Pork | 10 | 30 | | Fat Mutton | 10 | 27 | | Beans | 10 | 22 | | Beef | 10 | 17 | | Hare | 10 | 2 | | Veal | 10 | 1 | +----------------+---------------+----------------+

In the tropics, where little exercise can be taken, the waste of tissues is small, so that little nitrogenous food is required, and only a moderate amount of fat is taken; the need of heat-producers is comparatively small, so that starchy products, as millet and rice, are the principal articles of food. But gradually as we come north there is a marked increase both in the fatty and nitrogenous articles of food, until in the Arctic zone oily substances and animal food are the staple articles of existence, the amount of them that an Esquimaux will eat being something almost incredible, yet necessary to resist the severe cold.

The vegetable kingdom alone can supply all that is necessary for the human body both of flesh-forming and heat-producing substances, and we must not for a moment imagine that animal food is the only source of flesh-formers, as the world’s population is supported to a large extent on vegetable products, especially in tropical regions, while in colder climates, where vegetable products are hardly to be obtained, flesh and fat are indispensable. Thus man is clearly omnivorous; while men may be advantageously almost vegetarians in one climate, mixed eaters in another (as with us), and almost exclusively flesh eaters in a third, as in the Arctic regions. But there are some people who live exclusively on a vegetable diet (vegetarians) in our country, believing that such a diet is right in principle. Only those are true vegetarians who exclude milk, butter, eggs and cheese, as these are the very essence of animal food.

Man is capable of deriving all that is required for living and working from the animal or vegetable articles of food, either separately or combined. The question, therefore, is whether a purely vegetable diet or a mixed diet of vegetable and animal food is the better suited for our existence. To judge the question we have some facts to go upon. (1) We are so physically constructed as to be able to derive our nourishment from both animal and vegetable food. (2) In the Arctic regions hardly any vegetables are to be obtained. (3) Man alone has the intelligence to obtain food from all sources, and, by cooking, to render it fit for nourishment. It apparently follows, therefore, that while we are suited for either diet, or rather a combination of both, we may also select to some extent our diet according to our individual taste, habit of body, and other circumstances, as work and climate, experience having taught us that for the enjoyment of good health our diet must be regulated by the circumstances we have mentioned.

_Nutritive values of Foods._--The following tables, based on those published by Letheby,[2] show the nutritive values (per lb.) of various food-stuffs, with their composition.

(_a_) ANIMAL FOOD-STUFFS.

+-------------------+---------+----------------+----------------+ | | Value | Carbon. | Nitrogen. | | | per lb. | | | +-------------------+---------+----------------+----------------+ | | _d._ | Grains per lb. | Grains per lb. | | Butter, fresh | 16 | 6456 | -- | | Butter, salt | 12 | 4585 | -- | | Lard | 9 | 4819 | -- | | Bacon, dry | 9 | 5987 | 95 | | Cheese, cheddar | 8 | 3344 | 306 | | Beef | 8 | 1854 | 184 | | Bacon, green | 8 | 5426 | 76 | | Suet | 7 | 4710 | -- | | Pork, fat | 7 | 4113 | 106 | | Dripping | 6 | 5456 | -- | | Mutton | 5 | 1900 | 189 | | Herrings, red | 4 | 1435 | 217 | | Cheese, skim | 3 | 1947 | 483 | | Liver, bullocks’ | 3 | 934 | 204 | | White fish | 2 | 871 | 195 | | Milk, new | 2 | 599 | 44 | | Milk, skimmed | 1 | 438 | 43 | | Buttermilk | ½ | 387 | 44 | | Whey | ½ | 154 | 13 | +-------------------+---------+----------------+----------------+

(_b_) VEGETABLE FOOD-STUFFS.

+-------------------+---------+----------------+----------------+ | | Value | Carbon. | Nitrogen. | | | per lb. | | | +-------------------+---------+----------------+----------------+ | | _d._ | Grains per lb. | Grains per lb. | | Sugar | 5 | 2955 | -- | | Cocoa | 4 | 3934 | 140 | | Oatmeal | 2 | 2831 | 136 | | Pearl barley | 2 | 2660 | 91 | | Rice | 2 | 2732 | 68 | | Flour, seconds | 1½ | 2700 | 116 | | Bread, bakers’ | 1½ | 1975 | 88 | | Rye meal | 1¼ | 2693 | 86 | | Peas, split | 1 | 2698 | 248 | | Maize meal | 1 | 3016 | 120 | | Barley meal | 1 | 2563 | 68 | | Carrots | 1 | 508 | 14 | | Parsnips | 1 | 554 | 12 | | Beer and porter | 1 | 274 | 1 | | Treacle | 1 | 2395 | -- | | Potatoes | ½ | 769 | 22 | | Turnips | ½ | 263 | 13 | | Vegetables, green | ½ | 420 | 14 | +-------------------+---------+----------------+----------------+

_Digestibility of Foods._--There cannot be the least doubt that in the matter of digestion no rule holds good for all stomachs alike, and it is absurd to attempt to lay down a hard and fast line. At the same time, some idea of the relative period required to digest various substances may be gained from a study of the published results of experiments, though one very doubtful element is left out of the case altogether, namely, the quality of the cooking, which every one knows influences the digestibility of the food. The most complete list is that by Dr. Beaumont, from observation of the process in the stomach of a wounded soldier.

This may be compared with the following table of precedence in digestibility of some animal foods, on the authority of Chambers:--

Sweetbread and Lambs’ Trotters. Boiled chicken. Venison. Lightly Boiled Eggs, New Toasted Cheese. Roast Fowl, Turkey, Partridge, and Pheasant. Lamb, Wild Duck. Oysters, Periwinkles. Omelette (?), Tripe (?). Boiled Sole, Haddock, Skate, Trout, Perch. Tripe and Chitterlings. Mutton. Roast Beef. Boiled Beef. Rump Steak. Roast Veal. Boiled Veal, Rabbit. Salmon, Mackerel, Herring, Pilchard, Sprat. Hard-boiled and Fried Eggs. Wood Pigeon, Hare. Tame Pigeon, Tame Duck, Goose. Fried Fish. Roast and Boiled Pork. Heart, Liver, Lights, Milt, and Kidneys of Ox, Swine, and Sheep. Lobsters, Shrimps, Prawns. Caviare. Smoked, Dried, Salt, and Pickled Fish. Crab. Ripe Old Cheese.

The contradictions are sufficiently glaring.

From some recent experiments by Jessen it would seem that raw meat is more digestible than cooked, which is perhaps not astonishing when due allowance is made for the way in which that operation is often performed. Thus the times required for digestion were:

Raw beef, shaved fine 2 hours. ” mutton 2 ” ” veal 2½ ” Boiled beef, half done, shaved fine 2½ ” Raw pork 3 ” Boiled beef, well done, shaved fine 3 ” Roast beef, half done, shaved fine 3 ” Roast beef, well done, shaved fine 4 ”

Klenze, experimenting on 18 kinds of cheese, found that cheddar was digested in the shortest time (4 hours), while unripe skim Swiss cheese required 10 hours for solution. There is no difference in the digestibility of all sorts of hard cheese, or all soft cheese, but all fat cheeses are dissolved the most rapidly, because, being open by reason of the fat, they are the more readily attacked by the solvent. There is no connection between the digestibility and the percentage of water present in the cheese, but there is some connection with the percentage of fat and the degree of ripeness.

_Animal Foods._--There is surely no need to insist on the value of animal foods. At the same time there can be no doubt of a general tendency among town dwellers to eat too much meat. Twice a day is quite often enough for a meat meal, and then it should not form more than about ⅕ of the whole meal. Fresh fish is an excellent and wholesome substitute for meat, especially in the case of brain workers. Cheese is highly nutritious, but digestible only by those living out of doors; this does not apply, however, to the soft cream-cheeses. Lard, dripping, butter, and even butterine or bosch, have great value as heat-producing foods.

_Vegetable Foods._--Few people rightly estimate the true value of vegetables, apart, that is to say, from the starchy products of the vegetable kingdom, such as potatoes, sago, rice, &c. Many people hardly think of eating cabbage or spinach with their meat, yet there is no more wholesome food as an adjunct to the dinner table. The same may be said of many other vegetables. On the authority of the _Medical Record_, asparagus is a strong diuretic, and forms part of the cure for rheumatic patients at such health resorts as Aix-les-Bains. Sorrel is cooling, and forms the staple of that _soupe aux herbes_ which a French lady will order for herself after a long and tiring journey. Carrots, as containing a quantity of sugar, are avoided by some people, while others complain of them as indigestible. With regard to the latter accusation, it may be remarked, in passing, that it is the yellow core of the carrot that is difficult of digestion--the outer, a red layer, is tender enough. In Savoy the peasants have recourse to an infusion of carrots as a specific for jaundice. The large sweet onion is very rich in those alkaline elements which counteract the poison of rheumatic gout. If slowly stewed in weak broth, and eaten with a little Nepaul pepper, it will be found to be an admirable article of diet for patients of studious and sedentary habits. The stalks of cauliflower have the same sort of value, only too often the stalk of a cauliflower is so ill-boiled and unpalatable that few persons would thank you for proposing to them to make part of their meal consist of so uninviting an article. Turnips, in the same way, are often thought to be indigestible, and better suited for cows and sheep than for delicate people; but here the fault lies with the cook quite as much as with the root. The cook boils the turnips badly, and then pours some butter over it, and the eater of such a dish is sure to be the worst for it. Try a better way. What shall be said about our lettuces? The plant has a slight narcotic action, of which a French old woman, like a French doctor, well knows the value, and when properly cooked is really very easy of digestion.