Introductory lecture delivered at the commencement of the winter session 1864-65, in the Medical School, Surgeons' Hall, Edinburgh / by Stevenson Macadam.
- Date:
- 1864
Licence: Public Domain Mark
Credit: Introductory lecture delivered at the commencement of the winter session 1864-65, in the Medical School, Surgeons' Hall, Edinburgh / by Stevenson Macadam. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![diets of the population of our prisons and workliouses show, that a knowledge of the princi])les which ought to regulate the diet of a people has not received that professional attention which the im- portance of the subject demands. Tlie first attempt at a proper scientific classification of diet was made by Liebig, who divided the elements of food into heat-'pro- ducing ixndi fksh-fonning; and he likewise noticed the importance of the saline substances which generally accompany and are par- taken of along with the more ordinary food. Dr Edward Smith has recently gone into the whole subject of the classification of food -with the greatest care, and he is inclined to determine the value of the components of food according to the quantity of carbon and of nitrogen. This view is practically the same as that of Liebig; for tlie heat-2)roducing elements of food are those whose carbon can be readily burned within the living system, and thus supply the animal warmth ; whilst the jlesh-forming ingredients are those which con- tain nitrogen^ and whose particular office in the living frame is to replenish the flesh or muscle which is daily being disintegrated, and the momentary destniction of which, constitutes the ordinary wear and tear of the animal system. The relative proportions of the heat-producing or carbon elements and the fiesh-forming or nitrogen elements of food vary much, and the cost of their purchase, likewise, differs gi-eatly in even the more common articles of ordinary consumption. Besides, there is the important question of the relative digestibility of the various in- gredients found in food, as exemplified in the cases of starch, gum, sugar, and oil, on the one hand, and lignin or Avoody fibre on the other; the latter being as strictly one of the heat-producing or carbon elements of food as either of the former. A good instance of the difference of the feeding value of similar substances occurs in the case of white bread and brown bread. The former or white bread, when dried at 212° F., yields about 2'27 per cent, of nitrogen, which is equal to 14'8 per cent, of flesh-forming ingredients; whilst the brown bread contains about 2'63 per cent, of nitrogen, which is equivalent to 16*43 per cent, of flesh-forming ingredients. The brown bread, therefore, wliich is made fi'om the whole grain, is richer in nutritive matter than the white bread; but the husky part of the grain which is present in the brown bread, and contains some of the nitrogen, is much more difficult of digestion than the finer flour. Moreover, the brown bread, from the com])arative gi'itty character of the husk, causes an irritation in the alimentary canal, and tends to purge the individual, and thus causes the nutritive matters to pass out of the system before time has been allowed for their proper digestion and assimilation. In fact, the bran acts medlcmally, and a knowledge of its tendency to physic is veiy much the reason of its employment in part by the better classes. Tlie giving of brown bread to the farm labourers of England has proved that the diet is not a satisf^ying one, and its adoption in some of the prisons for a short time led to the exhibition of symptoms of](https://iiif.wellcomecollection.org/image/b2191638x_0007.jp2/full/800%2C/0/default.jpg)
