THE UNDISSOLVED, THE DISSOLVED AND THE GASEOUS END-PRODUCTS OF 11IETABOLISM.
The feces consist of those parts of the food and of the secretions of the ga-stro-intestinal tract and its glands which are not reabsorbed. Their condition depends upon the amount and the composition of the food, and also upon the condition of the gastro-intestinal tract and its functional activity, though this latter does not interest us here. We must emphasize the fact that any increase in the food above the actually necessary amount will also increase the amount of fecal matter. Canierer gives the following amounts and compositions of feces: In the experiments of Erich Milller an average of Sti.S per cent. of the nitrogen in the food were absorbed and 13.2 per cent. were excreted in the feces (inclusive of intestinal juice). The maximum of nitrogen absorption in these tests was 93.0 per cent., the minimum was 81.7 per cent.
Rubncr found that the adult who drank 2500 c.c. of milk per client excreted 5.07 per cent. of the ingested energy in the feces; Schlossmann and Moro found that when cow's milk was enriched by the addition of cream 96.6 per cent. of the solids were absorbed, 96.5 per cent.. of the fat and 95 per cent. of the nitrogen. Following are the figures found by The amount of urine in children after the nursing period is well known from many observations. As stated by Camerer the amounts do not increase in proportion to the amount of food, together with age and weight, but more slowly, and this is especially so in boys, while the concentration and the contents in urea increase rapidly in the latter in consequence of violent exercise, especially in older boys, and the consider able amount of perspiration which far exceeds that of younger children and of adults. Camerer's averages for the different ages may be found in Table 13; we know, that we will observe great variations, as may be seen from Table 14, composed by Sommerfeld: All of the cases in Table 1 I are either convalescents of acute infec tious diseases or surgical cases without lever a days before their discharge from the hospital. F.xttininatimi of the urine revealed nothing pathological. Diet was according to one of the forms given on page I.
In Anna Schabanowa's tests on children the specific gravity of the urine between the ages of two and six years was front 1010 to 1013 and between seven and thirteen years from 1010 to 1010.
In Table 111 we give the composition of the urine of older healthy children with special reference to the different components in regard to the nitrogen excretion: I. Average twenty-four-hour excretion of two boys of three years according to Camerer, Jr. Food: mixed diet, milk, meat, vegetables, potatoes. eggs, bread, and considerable water.
II. Averages from four girls of three years. Food : milk, 1 litre, and some mixed diet, Camerer, ,Jr.
III. Twenty-four hour average from a ten-days' test on a girl of seven years. Food: milk, 1000 c.c.: zwiebach, 1.50 Gm.; egg, 140 Gm.;
meat, 100 Gm.; vegetables cooked in milk, 100 Gm.
IV. Average from an eight-day test on a boy of seven years. Food: milk, 1000 c.c.; rolls, 150 Gm.; butter, 25 Gm.; vegetables, 100 Gin.; broth, 250 c.c.; meat, 125 Gm.
V. Average from an eight- to nine-days' test on a girl of seven years. Food: same as III.
VI. Average from a twelve-days' test on a girl of eleven years. Food: rolls, 250 Gm.; butter, 3.5 Gm.; vegetables, 200 Gm.; meat, 125 Gm.; milk, 1000 c.c.; cocoa, 30 Gm.; broth, 250 c.c.
The following particulars remain to be noted: According to the investigations of Goppert the excretion of uric acid varies so considerably in older children that it is impossible to give normal values. With equal quantity and quality of food uric acid corre sponds to urea and this proportion depends upon the quality of the food but not upon the quantity of nitrogen ingested. The proportion of the ethereal sulphuric acid to the entire production of is always the same though the absolute quantity varies considerably. Langstcin and Steinitz found the proportion of carbon to nitrogen as 0.6 to 0.7. The mineral constituents of the child's urine do not differ materially from those of the adult, though in the older child the urine contains much more sodium chloride than in the nursing infant.
The amount of sodium chloride in 100 c.c. of urine bet \Veen the ages of three and five years is about 1 Gin., between six awl eleven years, Gin. About .5 Gm. of sodium chloride per kg. of body-weight is excreted in the urine. Suet beer found the amount of lime in the urine of a girl of six years .155S per diem; Tobler for a boy of eleven years .103 Gin. According to Soetbeer the relation of phosphorus to lime is 1 to 12.
Carbohydrates and fat are excreted as CO, and except a small amount (see p. 440) which varies with the quantity and quality of the food and leaves the body with the feces unused. Scherling (in 1893) found that of this whole amount of CO, is excreted through the skin. About S5 per cent. of the nitrogen in the nitrogenous food is absorbed and 15 per cent. are found in the feces (assuming again a sufficient but not an excessive amount of food). That part of the absorbed nitrogen which is not used for retention is excreted in the urine.
E. Muller found (in children of from three to six years of age) that 30 per cent. of the water which is either consumed or formed are excreted in the urine (though Camerer's figures are considerably higher), 7 per cent. in the feces and 57 per cent. through the perspiratio insensibilis. Accord ing to E. Milner the evaporation of water from the skin compares to that through the lungs as ISA') to 24.8 or as 100 to 131.
Of the mineral constituents which are not retained we find in the young child (from two to four years old) about 50 per cent. in the urine and the same amount in the feces; in older children about 25 per cent. in the feces and 75 per cent. in the urine.