AXIUA1 FOOD.] 



CHEMISTRY. 



343 



mutton ; for it is the gelatine diffused through the broth 

 which converts the whole, when cool, into a jelly. 



Is the difference in the taste of the flesh of different 

 animals, so familiar to us in ordinary life, traceable to 

 certain differences in the composition of their food ? The 

 taste of fieldfares, for instance, after eating juniper- 

 berries, and that of some ducka and other aquatic birds 

 which feed on snails, crabs, and fish, and whose flesh 

 ubles train-oil, evidently settles this question in the 

 affirmative. In Tahiti the swine were fed on fruits only ; 

 and while their fat had nothing of the rich taste of 

 European pork, Forster compared their flesh to veal. 

 Science, however, answers the question with special regard 

 to the fats ; by its exact comparisons, it correctly ex- 

 plains the every -day experience of domestic life. There 

 can now be no longer any doubt that the substances with 

 which we feed our oxen, swine, and fowls, and stuff our 

 geese namely, turnips, potatoes, sawdust, maize, rice, 

 with several other seeds are remarkable for abundantly 

 containing the constituents of fat ; for in these kinds of 

 food, the substances contained in greatest quantities are 

 starch and sugar, with other similar matters, which the 

 animal body transforms into lactic and butyric acids, and 

 some other fats. Game, again, owes its savoury taste 

 in great part to its large proportion of krcatiue. Fat- 

 tening causes the quantity of kreatine to decrease. 

 }'-.i i '!_," '.s lose their taste if cooped-up and fed like 

 fowls, as is sometimes done in severe winters, 

 to protect them from cold. Tame ducks, if left at liberty, 

 beooii. lean, but acquire the agreeable flavour of game. 



ugh it does not require a sentimental mind to 

 regard the cramming of geese with a degree of aversion, 

 yet man has not disdained much more cruel encroach- 

 ments on animal life, with the intention of procuring a 

 new titillation to the palate. Not only has he made capons 

 and poulards of cocks and hens by mutilation, but he has 

 mutilated several Mammalia, as well as carps, in th same 

 manner. Chemical research has not yet discovered why 

 the flesh should become by this process more tender and 

 savoury ; but the fact is undoubted. Cows grow fat 

 more rapidly after the loss of their ovaries. The practice 

 of baiting, carried on in former times, but at present 

 only existing in the form of hunting, liquefies the fibrine, 

 which is the least readily soluble alimentary principle of 



and renders the meat more tender. 

 47. The intestines of some animals, the entrails in 

 which sausages are made, the brain, the liver, the kidney, 

 the spleen, and the sweet-bread, are very similar to flesh 

 in the properties of their constituents ; the differences 

 being chiefly in their quantitative proportions. Liver, 

 silicon, sweet-bread, brain, and kidneys, contain soluble 

 albumen in remarkable abundance. In addition to this 

 quantity of albumen, the sweet-bread contains much 

 gelatinous tissue, and an extremely small proportion of 

 fat ; while in the brain and liver, a considerable quantity 

 of phosphorus fat is intermingled with the ordinary 

 alimentary principles. 



In the bones, the nitrogenised alimentary principles 

 are almost exclusively represented by the gelatinous 

 las. Though there exists no doubt that gelatine is 

 ansformed into albumen, yet this 

 transmutation takes place so slowly that the bones alone 

 cannot yield a proper nutriment. Since gelatine, as 

 , is not present in the blood, it has therefore to be 

 formed into albumen in order to become one of its 

 ituents ; it is much more difficult of digestion than 

 albumen, in spite of its facile solubility in the gastric 

 juice. The bones are not deficient in fat and the more 

 important salts ; but as these pass only in part into the 

 cakes made of the gelatine of bones for the preparation 

 of broth, the use of these cakes as a principal supply 

 of food is to be reprobated. In England, which excels 

 all other countries in the preference of its people for a 

 substantial nutriment, these cakes are prepared from the 

 broth of meat inspissated by boiling to a jelly. Some- 

 timos, indeed, bones and other parings may be used in 

 addition ; but fresh beef furnishes the essential constituent 

 of the inspissated juice, which is poured into small cake- 

 moulds. These cakes, when dissolved, closely correspond 



with real broth ; and they therefore justly claim for 

 themselves the name of portable soups. What in France 

 is sold under the name of bouillon-cakes, is nothing but 

 gelatine ; a production difficult of digestion, only slightly 

 nutritious, and therefore objectionable. No economy is 

 so nearly related to extravagance, as that of preparing 

 soups from such cakes in order to effect a saving in meat ; 

 for this broth does not repair the expenditure of the 

 body ; and while impoverishing the purse, fails to enrich 

 the blood. 



48. Eggs of Birds as Food. No other aliment unites 

 so completely the advantages of meat, as the eggs of our 

 domestic birds. The yolk and white consist chiefly of 

 albuminous matters the yolk, of caseine and albumen ; 

 the white, of soluble albumen, containing more sulphur 

 than blood and of an albuminous body containing a 

 large quantity of sulphur, scantily soluble, and forming 

 cellules in the shape of small membranes, which include 

 the soluble albumen. 



Wo have before explained why eggs coagulate when 

 boiled. The heat of the boiling- water being communi- 

 cated through the shell to the thick albumen solution, 

 the albumen becomes hard. 



The white of egg contains more water than the yolk ; 

 somewhat more than one-half of the latter, but only 

 four-fifths of the former, consisting of water. The yolk is 

 also, in a nearly similar proportion, richer than the white 

 in fat and in albuminous substances. The yellow oil of 

 the yolk contains a large quantity of oleine, with a little 

 margarine, less phosphorous fat, and still less gall-fat. 



What further does the egg require to represent a com- 

 plete nutriment ? Nothing but the salts and chlorine 

 compounds of the blood ; and all these are found in the 

 inorganic constituents both of the white and yolk. 



49. Animal Food Considered. "Flesh makes flesh." 

 Thus says a popular proverb. We readily agree with 

 this view, and that so much the more when we regard 

 diet in its direct relation to our body, since the view is 

 much more correct than if it had been said " Flesh 

 makes blood." It is not only the potash predominating 

 in the flesh which distinguishes it from the blood, tho 

 latter containing soda in a greater proportion ; for while 

 in the blood more albumen than fibrine is to bo found, 

 tho nbrine predominates over tho albumen in tho mus- 

 cles. Flesh, therefore, is much more capable of repairing 

 tho waste of our muscles than blood. 



Is this discordant with the fact, that all nutriments 

 find their way to the tissues only through tho blood ? 

 Tho chyle, originating from meat, is, like all the rest, 

 !i;d with tho blood, to which it is conveyed through 

 the thoracic duct. But as our flesh in great part con- 

 sists, not by chance, but according to a necessary law of 

 attraction, of chloride of potassium, phosphate of potash, 

 and fibrine, an abundance of these constituents in the 

 blood must be to the benefit of our muscles. 



Under a predominant, and still more under an exclu- 

 sive animal diet, the fibrine does, in fact, pass in greater 

 quantity into the blood. The natural result of this is 

 great vigour of muscle, as may be illustrated by the 

 strong muscular structure and fiery movements of tho 

 Indian tribes, in North and South America, who snatch 

 a livelihood from the chase. Has not breeding cattle 

 tho same influence upon the Calmucs and Tartars, tho 

 pastoral tribes of the Alps, and the mountaineers of tho 

 Scotch Highlands ? Who does not know the superiority of 

 an English labourer, who is strengthened by his roast 

 beef, over an Italian lazarone, whose predominant vege- 

 table diet explains in great measure his inclination to 

 idleness 1 And, finally, the slighter strength of the 

 Laplanders and Samoyedes, of the Greenlanders and 

 Kaintschat dales, whose food consists almost wholly of 

 fish, in which scarcely more than three-fourths of the 

 fibrine found in the birds and animals is to be traced, is 

 an additional proof of the truth of the sentence "Flesh 

 makes flesh." 



The richer the meats are in soluble albumen, the poorer 

 are they in fibrine and fat, the more easily digestible 

 will thoy be, if other constituents do not neutralise this 

 property. Thus the flesh of pigeons and fowls is more 



