The choice of food / by Henry Simpson.

  • Simpson, Henry.
Date:
[between 1870 and 1879?]
Catalogue details

Licence: Public Domain Mark

Credit: The choice of food / by Henry Simpson. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    11/22 (page 89)
    the sugar found in milk. All these varieties of sugar differ in some respects from each other. There are also other substances, as gum, and cellulose, or the woody fibre of vegetables. Sugar and starch exist in large quantities in many of our common foods, and I shall have to say something by-and-by about the latter in the feeding of infants. Sugar is readily dissolved, and can be absorbed from the ahmentary canal, but in all probability cane sugar is changed into grape sugar before this takes place. This latter and the sugar of milk seem to act in the system in the ;ame manner. Now before starch can be applied to the uses of the body, it must be converted into sugar, which is effected in great part by the action of the saliva in the mouth. Unless this change takes place it is only so much useless matter, which has to be got rid of. When starch is examined under the microscope, it is found to con- sist of little bodies of various sizes and shapes, according to the source from which they are obtained, whether from wheat or the potato, or as found in the different kinds of arrowroot, which are starches prepared from various tuberous roots. These little granules ire so hard that unless the starch is cooked before being eaten, this change into sugar cannot take place, and it passes away undigested. Boiling or exposure to heat in some other way bursts the granules, and so they can be easily acted on by the saliva. Vou will see, therefore, how necessary it is first of all to cook all starchy food, and next to chew or masticate it well, so that it nay be submitted to the action of the saliva. When starchy food s swallowed, the action of the saliva is put a stop to by the action of the acid gastric juice, and its digestion is suspended. On leav- ng the stomach, however, the juices of the pancreas and of the glands of the intestinal walls act energetically on starch, and probably the greater part is digested after it leaves the stomach. Well, now, these carbo-hydrates serve somewhat the same purposes as the fats or hydro-carbons. There is no doubt that they can produce fat in the body, although it is only recently that this has been satisfactorily proved, But for this purpose they must be taken along with nitrogenous food and salines. As force-producing agents they take a lower place than the fats, but are easier of digestion. Now we must see what part the inorganic matters—water and salines—play in our bodies, and why they are required in food. Life, as we have before said, consists in change, and without the