FLESH FOOD.] 



CHEMISTRY. 



341 



and of substances not nitrogenised, more inorganic than 

 organic matter. Lean meat is the food which most com- 

 pletely answers these conditions. 



Substances from each of the other groups, however, 

 as we have just mentioned, are equally indispensable, 

 though requisite in difl'erent quantities. Compounds of 

 chlorine, salt, fat, and constituents of fat, are as 

 absolutely necessary as albumen or gelatine. It always 

 betokens a narrowness of view, therefore, to speak of 

 any aliment as innutritious. It is true, potatoes are 

 less nutritious than meat, because the latter is very 

 similar to the blood ; while potatoes contain very little 

 albumen and a large proportion of starch : but in the 

 unqualified assertion that potatoes do not nourish at all, 

 we forget that starch is transformed into fat by the 

 digestive process, and that this represents an essential 

 constituent of the blood. Potatoes, combined with a 

 certain proportion of white of egg, become as nourishing 

 as milk or meat. 



To distinguish, in one word, between digestibility and 

 nutritiveness, we may say, that the former expresses the 

 rapidity with which the alimentary principles of an ali- 

 ment are transformed into constituents of the blood ; 

 the latter, the quantity of alimentary principles con- 

 veyed to the blood by solid or liquid food. Hence it 

 follows, that we can speak of digestibility with respect to 

 the alimentary principles as well as the compounded 

 I aliments, but of nutritiveness only with respect to the 



/LID FOOD. 42. Meat and Eggs. In regarding 

 the different kinds of food, from the whale-oil of 

 the Greenlanders, and the bear's-grease which forms 



i an article of diet in a Mogul tribe, up to the refined 

 cookery of the wealthy in the more civilised countries 



: of the globe, where, for instance, oysters and trepang 

 (a small tubular animal belonging to the class of the 

 Radiata) are favourite dainties, we soon find out that 

 there exists no class of animals which does not furnish 

 some contribution to the food of man. By all civilised 

 nations, however, the flesh of herbivorous animals is 

 preferred. 



In this respect we may assert that the plants first pre- 

 pare the food of man. It is an art in which they excel 

 that of preparing excellent meals from very simple 

 materials. It is true that those plants which prepare the 

 most nutritious food, take also up some compounded 

 organic aliments ; but it is also undeniable that plants 

 can live exclusively on carbonic acid, ammonia, water, 

 and some inorganic substances, and in every case derive 

 from these simple alimentary principles the chief bulk of 

 their body. The carbonic acid, the ammonia (a very 

 simple combination of nitrogen with hydrogen),* and the 

 water, are all three constituents of the air. " While the 

 animal swallows bodies already formed," says Forster, 

 who, before all others, deserves to be called the naturalist 

 of the people, " these fine tubular and cellular formations 

 eagerly take up the simplest elements from the air. 

 Woven by sunshine and ethereal fire, such as formerly 

 poets only dared to dream of, the soft green of the 

 woods and fields smiles upon our sight ; and, behold ! 

 in the infinitely delicate network of the blooms and 

 ripening fruits, glows the sevenfold beam, and adorns 

 the vegetable world with the manifold brilliancy of 

 its hues !" 



Animals living on plants not unnaturally convey the 

 impression of a greater purity upon our fastidious senses, 

 which are offended by the rancid smell of the carnivorous 

 Mammalia, and by the oily flavour of the birds of prey. 

 Hence our predilection for the herbivorous animals ; and 

 among these tlio Ruminants and the many-hoofed occupy 

 the first place. Throughout the whole of Central Europe, 

 no meat is consumed in greater abundance than beef 

 and pork. 



43. Constituents of Beef . The flesh of oxen, or beef, 

 illustrates the composition of all other kinds of meat. 

 We may take the composition of beef as the standard, 

 with which, the varieties of the other most common 

 animal aliments may be compared. 



See ante, p. 323. 



In beef, as in all aliments which, when taken to the 

 exclusion of all other food, are able to maintain human 

 life, the three groups of simple alimentary principles are 

 represented. A combination of albuminous and fatty 

 matters, of compounds of chlorine and of salts, abun- 

 dantly diluted with water, is all that is necessary to 

 sustain life. 



The albuminous substances of beef are the fibrine of 

 the muscles and albumen proper. The former constitutes 

 the finest fibres of flesh ; the latter is the essential body 

 of the nutritious juice which occupies the space between 

 the solid parts. The flesh owes its red colour to the 

 blood which it contains in very numerous vessels ; and 

 this blood comprises albumen, globuline, fibrine, and 

 traces of caseine ; and in addition to these albuminous 

 substances, some colouring matter containing iron. 



The albuminous substances which animal food thus con- 

 tains, are not the only supply it affords, to compensate 

 for the albuminous matters of the blood lost with the 

 excretions ; for the finest muscular fibres are enclosed in 

 the cellular or binding tissue which unites them into 

 bundles. This tissue, when boiled, yields gelatine, which 

 is soluble in water. In the body, gelatine is again trans- 

 formed into albumen. Convalescents very often regain 

 their strength by the almost exclusive use of jelly from 

 bones ; and gelatine is the only nitrogenised body con- 

 tained in any large amount in this jelly. As the blood of 

 man, however, does not contain gelatine, as a necessary 

 condition of its regular combination, but albuminous 

 matter, we must infer that the gelatine is transformed 

 into albuminous compounds. 



That the cellular tissue in the muscles is intermingled 

 with elastic fibres, does not in any way affect the nutri- 

 tious properties of animal food ; for these elastic fibres 

 are not dissolved in the digestive fluids. They constitute 

 a part of those alimentary remnants which, united with 

 certain excretory substances of the blood, compose the 

 excrements. 



Like gelatine, the horny cells lining the walls of the 

 muscular blood-vessels are entitled to the name of con- 

 stituents of albumen. They are, however, of small 

 importance ; for their quantity is so insignificant, that 

 even if soluble in the alkaline secretions of some digestive 

 glands, they are less digestive than the fibres yielding 

 gelatine. 



Kreatine, flash-basis, and flesh-acid, are regular nitro- 

 genised constituents of beef. Are they to be considered 

 as alimentary principles ? There is scarcely any doubt 

 that they pass into the blood, and from the blood int< > 1 1 1 . 

 muscles. But is mercury a nutriment because it passes 

 through the blood into the cellular tissue of the bones, 

 and is found there in the form of small globules ? Against 

 this opinion the judgment of even the unprofessional 

 reader protests. And the kreatine, the flesh-basis, and 

 the flesh-acids, we cannot consider to be, strictly speak- 

 ing, alimentary principles, as they belong to the regres- 

 sive transformation, which process, by the action of 

 oxygen, conveys all organic matters of our tissues to the 

 excretory glands. The organic compounds without 

 nitrogen, contained in beef, are much less various 

 than the nitrogenised. The former consist of several 

 fats, sugar, and lactic acid. We have often mentioned 

 that the fat of the Ruminants owes its hardness to the 

 stearine. This is associated with margarine and oleine ; 

 whilst the peculiar fat containing phosphorus, as well as 

 the gall-fat of the nerves and the blood, scarcely deserve 

 any consideration, on account of their small quantity. 



Chloride of potassium, and phosphate of potash, are 

 the peculiar inorganic substances of the flesh. They 

 alone would be sufficient to distinguish the flesh from the 

 I . While the blood contains seventeen times more 

 soda than potash, there is in the flesh of the ox about 

 three times more potash than soda. Phosphates of soda, 

 lime, magnesia, and oxide of iron are contained in beof, 

 in somewhat considerable quantities ; but there are only 

 few traces of sulphates of the alkalies attributable to the 

 blood of the muscles. The amount of water contained 

 is so considerable, that, on an average, it amounts to 

 more than three-quarters of the whole mass. 



