Page:The American Cyclopædia (1879) Volume VI.djvu/110

 102 DIETETICS meat has a great influence upon its digesti- bility ; that which agrees best with the major- ity of stomachs is broiling. The fire should be brisk, so that the albumen on the surface of the meat may be rapidly coagulated; this pre- serves the juices, and it is rendered at once more savory and more tender. The same rule applies to boiling and roasting. When the meat is to be cooked, if boiled, it should be at once plunged into boiling water ; while if soup is to be made, the meat should be put into cold water and the temperature slowly raised, thus extracting its nutritious fluids to the greatest possible extent. Of all methods of cooking, frying is the most objectionable ; not only is the meat rendered harder than when boiled, and thus more indigestible, but it becomes im- bued with boiling fat, and is thus rendered still more refractory to the gastric juice. Eich stews are objectionable on the same account. By the action of salt on muscular flesh, the juices of the meat are abstracted ; in this man- ner not only is its nutritive value impaired, but it is rendered harder and drier and conse- quently more indigestible ; the longer the flesh is exposed to the action of salt, the harder and drier it becomes. Perhaps all fats form an ex- ception to the fact that meat is rendered more indigestible by salting ; they have little water to lose, and their texture consequently cannot become consolidated; fat pork is even ren- dered more digestible by salting. St. Martin, according to Dr. Beaumont's observations, digested recently salted pork when raw or broiled in from 3 to 3i hours ; the same ar- ticle fried occupied him 4J hours for its reduc- tion ; while fresh pork, fat and lean, roasted, required 5 hours. On the other hand, boiled fresh beef with a little salt was digested in 2f hours, while old salted beef required 4% hours when dressed in the same manner. All em- pyreumatic substances impair digestion by in- terfering with the action of the pepsin, which is the principal solvent agent of the gastric juice. In this manner smoking impairs the digestibility of meat; few things are more difficult of management by a feeble stomach than old and well smoked beef. St. Martin found fowls, roasted or boiled, of slower diges- tion than beef; ducks and geese, as might be supposed from the amount of fat they contain, are assimilated with difficulty. There is, how- ever, so much variation in this respect in dif- ferent individuals, that the absolute digestibil- ity of an article of food can hardly be deduced from experiments on a single person. Fish furnishes % an abundant and digestible variety of food. The dry, white sorts, cod, haddock, bass, &c., are the most digestible ; while the richer kinds, salmon, shad, mackerel, eels, &c., I apt to agree with the stomach. St. Martin digested boiled or fried salmon trout in 1| hour, boiled dried cod in 2 hours, fried catfi>li in 3 hours 20 minutes, and boiled pickled salmon in 4 hours. Milk, the only food during the earlier months of infancy, con- tains from 12 to 13 per cent, of solid matter, about one half of what is contained in flesh ; it is poorer in nitrogenous and richer in carbon- aceous food ; its ash furnishes but O47 per cent, of iron, while those of flesh and wheat flour yield 1 per cent. It is not digested so quickly as would be supposed, and in this re- spect boiled has the advantage of unboiled milk; the one took St. Martin 2 hours, the other 2J, to convert into chyme. Milk dis- agrees with many persons ; this is often con- nected with the readiness with which it under- goes change when exposed to the atmosphere, and this change commences long before it can be recognized by the taste. Milk just drawn from the cow agrees perfectly with some per- sons who are unable to take it a few hours later. When cows are kept in an impure and confined atmosphere and badly fed, it .has been conclusively shown that their milk pro- duces disturbance of the digestive organs and diarrhoea in infants who are fed upon it. The caseine of milk, coagulated, generally mixed with more or less butter, and pressed so as to free it from the whey, constitutes cheese. Its richness varies with the quantity of butter it contains; some varieties, Stilton for instance, are made from milk to which an additional quantity of cream has been added. Salt is u to preserve it, and some kinds, as Dutch che< are very highly salted. When cheese is k for a length of time, it undergoes a number changes, partly dependent on the liberation the volatile fatty acids existing in the butter, partly, in the richer varieties, on the com mencement of putrefactive fermentation. Th firm, close texture of cheese renders it al- ways hard of digestion, and the rich and strong- smelling varieties are particularly to be avoided by delicate stomachs. Fresh sweet butter is, perhaps, the most wholesome and digestible of fatty matters; by heating or rancidity its digestibility is greatly impaired. Of farina- ceous articles, light well made wheaten bread, from 12 to 24 hours old, is the most gene- rally digestible ; warm bread is indigestible, because it forms a tough mass not readily penetrated by the saliva and rebellious to the gastric juices. Unleavened bread, maccaroni, and vermicelli are wholesome, and agree well with the stomach ; on the other hand, flour combined with fatty matter, whether in the form of pastry, cake, or pudding, is more or less indigestible, according to its texture and richness. Next to wheat flour, rye affords the best and most wholesome bread. In various countries oatmeal, barley, and maize are used as substitutes for wheat; they form kinds of bread wholesome enough for those habituated to their use, but apt to disagree with strangers. In tropical countries rice to a great extent takes the place of the other cereals, and per- haps a larger population mainly subsist on it than on any other single article of food. It affords very little of plastic or blood-making material, and hence when taken alone is con*