Morning journal and courier., 1880-03-03

were 1allaciOu6-Deen or great S6rVlce In throwing light upon the process of digestion. Thus it was learned that a meal of boiled venison steak will be digested and removed from the stomach in one and one-half hours, a much shorter time than required for other meat. Next in ease of digestibility comes mutton of proper age, and then beef, while pork is the most refractory to the gas trio juice. Of poultry, turkey is the most di- gestible, while ducks and geese. owing to the quantity of fat, are assimilated with difficulty. The lecturer now spoke of the additional di- gestive forces lying in the intestinal and the pancreatic fluids. Many interesting and com- plicated chemical actions take place during the passage of the food through these canals. We will simply point out the manner in which albuminous food is fitted for nourishing the blood, and then by contributing to the up- building of the body.
 Let us now try one or two experiments to fix more clearly in our minds the peculiar solvent action of the stomach and pancreatic juices in albuminous or nitrogenized foods. In this dish is an artificial gastric juice from pigs stomach, and in this an artificial pancre- atic juice prepared from OK pancreas or sweet breads as they are called. Both of these solu tions are heated to correspond to the body temperature, viz, 1OOe Fahrenheit. To each of these solutions we will add this quan- tity of blood fbrin, typical form of albu- men, and one which is very similar in nature to the tissue of beefsteak for example, a san- pie of which you see here being white in col or simply because it has been washed entirely free of blood and other attractive matters. The two mixtureswe will allow to stand for time and note later the changes which may take place. We have now followed the nitrogenous alimen- tary principles to the form of peptones. The precise nature of what now takes place is not fully known. We know that the peptones pass into the blood, becoming there without doubt incorporated in this moving tissue, but as to the steps in the process we haTe no definite data We know the ultimate products, but are unacquainted with the detailed changes which must take place. As regards the seat of the change we can only surmise that the liver is the workshop in which this substance un- dergoes the metamorphosis. The various nitrogenous principles of the body must be derived from it, but whether by direct trans formation or by passing through the stage of albumen we have no means of deciding. We know that arti6cially formed peptones are available for nutrition, for several investi gators found that dogs fed on peptones, and a small quantity of -nitrogenous food &C., cumulated flesh and gained quite rapidly in weight, and at present large quantity of ar tificially prepared peptones are annually manufactured at Amsterdam and throughout Europe, and perhaps in this country, as an ar- ticle of food, designed particularly for weak stomachs afflicted with scarcity of digestive juices. The professor now illustrated by ex- periments that peptones are formed by stom- ach and pancreatic digestion also the man ner in which peptones pass from the stom- ach and intestines into the blood. The power and great importance to life of ni- trogenous or albuminous matters as food was now considered. It is nitrogenous matter which starts and keeps in motion the molecu- lar changes which result in the phenomena of life. and it holds the same important position with regard to the secretions. These owe their active properties chiefly, if not entirely, to nitrogenous constituent. Thus pepsin, the active ferment of the gastric juice, contains nitrogen. The relation of nitrogenous
 The advantages of mixed diet over an en- tirely n1trogenous or albuminous one are all well stated by Huxley. "A healthy, full grown man keeping up his weight and heat, and taking moderate amount of exercise, eliminates 4 900 grains of carbon to only 300 grains of nitrogen" or roughly only needs 1-13th as much N. as 0. A man confined to a purely albuminous diet must eat prodiei- ous quantity of it. This involves waste of power. Hence instinct teaches us to mix fats aud starchy matters with albuminous foods, and these supplemented by salts found in the body and furnished by vegetable and other matters make up the total necessary foods for sustaining life.
 Digestibility and nutritive value bear no necessary relation to each other an article of food may be highly nutritive and yet exceed ingly indigestible. There are innate differ ences in kind as well as in degree in the diges- tive as in the intellectual powers of mankind. Food stands in definite relation to the con- ditions of life, habits and needs of persons, and habit, in particular, has a great influence on the digestive action what a person is ac- customed to, that he will digest with the greater facility. We have all doubtless expe- rienced the symptoms of indigestion brought about by a change of residence and subss- quent change of food, which though whole some our stomachs were unacquainted with. There is also statement in Q book on diges- tion which reads like this, ''that the digesti- bility of food is much influenced by our liking for it." and within certain limits it seems true what we are fond of agrees with us, and what we dislike is not apt to digest well. But aside from all these minor points certain articles of food are comparatively easy of di- gestion, while others are asslmilated with greater difficulty. In meat the degree of di- gestibility depends upon the proportion of fibre, gelatine and fat of which they are com posed and also upon their variation in mechanical texture.
 Whatever renders the animal fibre harder causes the meat to be less digestible on the other hand, whatever renders it more delicate and tender, more easily separated and disinte- grated, makes it more readily soluble in the juices of the stomach. Violent exercise just previous to death gives increased tenderness to the flesh, end it is owing to this fact that the flesh of wild animals is more tender than the flesh of domestic animals, since nearly all of the former are killed after more or less lengthy chase. It is generally believed that provided an animal has reached maturity the tenderness of it's flesh is increased by youth by it's not having been worked and by it's be- ing in good condition. Quite young flesh, however, is not so easily digestible; the flesh of the lamb and calf, for example, being less digestible than mutton or beef The fatty drofA 1o1 fofN matter are difficult of assimilating, being par ticularly offensive to weak stomachs, and when taken in large quantity remain in the stomach frequently as long as six hours, and being liquifed there by the heat of the body may incase other ar ticles of food and hinder their digestion but in small quantities it is readily absorbed and of great value as heat producer.
 The mode of preparing meat has great influence upon it's digestibility. Boiling is generally considered the method best adapted to easy digestibility, the reason being that the albumen on the outer surface becomes coagu- lated and the juices are kept within and the whole rendered thereby more savory and ten der. la the case of boiling meat the surface albumen should be coaguiated as soon as possible, thereby preventing the extraction of the soluble nutrient matter, and in such cases the meat should be plunged at once into boiling water, but in any case the boiled flesh
 
 piece would give if roasted. If, on the other hand, a soup is to be made, the meat should be placed in cold water and the temperature gradually raised, thus extracting it's nutrient qualities to the greatest extent. Of all the methods of preparing meat frying is the most objection able; the meat is not only rendered harder than when boiled and thus more indigestibIe, but it becomes imbued with boiling fat and is thereby rendered still more refractory to the gastric juice. Iu the process of salting or curing meat the juices of the meat are more or less extracted and it's nutritive value some what impaired, and the action of the salt also tends to render the meat harder and drier and consequently more indigestible. In the case of all fat meat as salt pork there is probably an exception to the rule that meat is rendered more indigestible by salting; they have but little water to lose and so their tissue cannot become more consolidated, and according to observations by Dr. Beaumont it is possible that fat pork is rendered more digestible by salting he found by experiment on St. Mar tin that recently salted pork when raw or boiled was digested in three hours; the same article fried was digested in four hours, while fresh pork roasted required five hours. On the other hand boiled fresh beef was digested in