Journal of the Chemical Society Abstracts
441 tities of American meat-flour were given to pigs, it was found that on an average 96.6 per cent. of the albumin and 87.3 per cent. of the fat contained in the latter were digested, and these coefficients were independent of the ratios in which the two kinds of food were administered. When on the other hand, besides a constant weight of potatoes, meatflour and wheat-flour were given in the ratio 1: 1-5-2.8, only 86.6 per cent. of the meat-flour albumin was digested, and the percentage rose
... e percentage rose again when starch was omitted from the diet. Young pigs fed on potatoes increased i n weight 1 kilo. for each 13 kilos. of potatoes ingested; the same increase in weight was produced by 1.8 kilos. of meat-flour; hence the nutritive value of the latter is to that of the former as 7-2 : 1. Ir, older animals ($0 kilos. in weight) 34.6 kilos. of potatoes or 1.21 kilos. of meat-flour produced a n increase of weight equal to 1 kilo. ; that is, 28.6 kilos. of potatoes had the same effect as 1 kilo. of meat-flour, or the nutritive value of the latter was relatively four times as great as in the former experiments. I n determining the value of food-stuffs, therefore, it is clear that no reliance can be placed on isolated experiments, since many circumstances map affect the results. I n two other sets of experiments the same increase in weight, 100 kilos., was produced, on the one hand by 1,451 kilos. of potatoes with 44 kilos. of meabflour, and on the other hand by 1,163 kilos. of potatoes with 104.5 kilos. of meat-flour, the total amount of dry matter in the two diets being the same. Above a certain limit, then, dry potatosubstance is as nourishing as dried meat-flour, the lstter being only advantageous when added to the former (or other foods poor in nitrogen) in sufficient quantity to aflord a moderately nourishing diet (albumin to other organic matters as 1 : 5). The authors have also found that vegetable and animal albumin are nutritive in nearly the same degree. This was proved by feeding animals-lst, on a diet composed of potatoes and peas, with a little linseed; and Znd, on a diet of potatoes, meat-flour, and starch, the total weight of digestible substances being the same in both, and the ratio of albumin to other organic matters 1 : 6. When starch was omitted from the second diet, and the amount of meat-flour increased so as to make the ratio of albumin to fat and carbohydrates greater than 1 : 4.5 (the total organic matter being still the same), no adclitivnal advantage resulted. Ch. B. Formation and Secretion of Ferments. By P, G R~~T Z N E R (Pjiiger's AYC?L~V. f. Physiologie, mi, .-According to Nussbaum, solutions of ferments uniformly possess the power of reducing perosmic acid, and those glands which secrete fluids capable of setting up fermentative actions contain cells which are more or less darkened by that reagent, whilst glands, the secretions from which are nonfermentative, are unaffected by it. The author disputes the generality of this rule : thus, the submaxillary glands of rabbits produce more darkening with perosmic acid than the parotid glands, whilst the secretion of the former is non-fermentative and that of the latter highly fermentative, and similarly in other cases.