On the proportion of nitrogen contained in alimentary substances taken from both the organic kingdoms as a comparative measure of their nutritive power.

  • Schlossberger, J., Dr.
Date:
[1845]
Catalogue details

Licence: Public Domain Mark

Credit: On the proportion of nitrogen contained in alimentary substances taken from both the organic kingdoms as a comparative measure of their nutritive power. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    ments, that which he calls the equivalent nutritive powers of these substances for the domestic herbivorous animals, and Thomson has also given one for those bodies which he exa- mined. We omit these tables, as we have the intention of constructing a table of our own for all the substances which are used as food by man, and which have been hitherto exa- mined in this respect. We may now proceed to the relation of our experiments. All the substances made the subject of observation were first carefully dried at 212’ F., and then analysed according to the method of Varrentrapp and Will, slightly modified to over- come some practical difficulties. Intermediate between animal and vegetable aliment, as daily observation leaches and chemical analysis confirms, is to be found the most general food of the young of the class Mam- malia, namely, milk. I. Cow’s milk. 0’404 gramme* of the dried residue, ob- tained by evaporating the fresh-drawn milk in the water-bath and subsequent desiccation at 212° P\, yielded 0'241 grm. of the ammonio-chloride of platinum, corresponding to 3*78 per cent, of nitrogen. II. 0’438 grm. human milk, treated as in the first experi- ment, gave OTl grm. ammonio-chloride of platinum, equal to 1*59 per cent, of nitrogen. Human milk is, according to most analyses, one of the poorest in caseine, and in this respect is very far inferior to that of the cow, but in consequence of this may probably be more easily digested. The amount of nitrogen in milk, which corresponds to that of caseine, comes much nearer to the pro- portion contained in vegetables than any other kind ol aliment from the animal kingdom. Of the substances obtained from milk and u.sed as food, we have examined only that of cheese, selecting four of the kinds most commonly used in Britain. III. 0'485 grm. of Dunlop cheese gave 0‘461 grm. of am- monio-chloride of platinum, equal to 6'03 per cent, of nitro- gen. IV. 0*475 grm. of Gouda cheese gave 0*532 grm. of ammo- nio-chloride of platinum, equal to 7*11 per cent, ot nitrogen. V. 0*444 grm. of Cheshire cheese gave 0*471 grm. of am- monio-chloride of platinum, equal to 6*75 per cent, of nitro- gen. * 4’he balance used in these analyses having been made by Deleuil of , Paris, and being only furnished with French weights, will account for the introduction of the word here, and in the other analyses throughout the paper. The French gramme is equal to 15*444 English grains.