The history of salt

by Evan Marlett Boddy

The general effect of digestion is the conversion of the food into what is called chyme; and though the various materials of a meal are entirely dissimilar in their composition, whether they are azotised or nitrogenous, and non-azotised or non-nitrogenous; when they are once reduced to this condition, viz., chyme, they hardly admit of recognition.

The reader may naturally suppose “that the readiness with which the gastric fluid acts on the several articles of food, is in some measure determined by the state of division, and the tenderness and moisture of the substance presented to it,” and he may also be aware of the fact, that the readiness with which any substance is acted upon by the gastric juice, does not necessarily imply that it possesses nutritive characteristics, for it stands to reason that a substance may be nutritious, and yet hard to digest; and when this is the case, the gastric follicles supply a greater quantity of fluid, in order to effect the conversion of the food into chyme. Pepsine and the hydrochloric acid, the two indispensable and inseparable solvents, are consequently secreted in greater abundance in order to meet and overcome the difficulty, so that the food may be in a condition fit for assimilation with the various tissues.

Man requires a mixed kind of aliment, therefore he must have animal as well as vegetable food, though there are many instances of people who live wholly on animal or vegetable substances; these of course are anomalies, and therefore their habits are unnatural. Vegetarianism is a foolish freak of the weak-minded and semi-ignorant; the structure of the teeth of man points conclusively to the fact that he is both carnivorous and herbivorous; though these vegetable philosophers would have us believe that he is destined to feed upon cabbages!

Food is divided into two groups, nitrogenous and non-nitrogenous, or animal and vegetable; the only non-nitrogenous organic substances of the animal, or nitrogenous, are furnished by the fat, and in some few cases by those vegetable matters that may happen to be in the organs of digestion of those animals who are eaten whole.

Nutritive or plastic, is given to those principles of food which are converted into fibrine or albumen of blood, and being assimilated by the various tissues through its medium, and those principles comprising the major part of the non-nitrogenous food, in the form of fat, gum, starch, and sugar, and other substances of a similar nature, are supposed to be utilised in the production of heat, and are termed calorifaciant, or sometimes respiratory food. The principal ordinary articles of vegetable food contain identical substances, in composition, with the fibrine, caseine, and albumen, which constitute the chief nutritive materials of animal food; for instance, the gluten which is present in corn is identical in composition with fibrine, and is therefore called vegetable fibrine; legumen, which exists in beans, peas, and other seeds of the leguminosæ, is similar to the caseine of milk; and albumen is most abundant in the seeds and juices of nearly all vegetables.

On carefully analysing the preceding remarks on food and some of its uses after it has been digested, and the composition and properties of the gastric juice, it is obvious that salt is not only a simple adjunct to food, and therefore not of much importance, but is an article of diet in every sense of the word, and as necessary, if not more so, than many aliments which are regarded as essential.

In its relations to animal or nitrogenous, and vegetable or non-nitrogenous, food, salt is in every respect important.

The hydrochloric acid of the gastric juice, which is so bountifully secreted by the glands of the stomach, of course drains the whole system of its salt, and especially does it draw the chloride of sodium from the blood, which contains 3·6 in 1000, being held in solution by the liquor-sanguinis.

Animal or nitrogenous food contains only a minimum of salt, which chiefly exists in the muscular tissue, its principal constituents being albumen and fibrine; if, therefore, it is eaten as a rule without salt, digestion is by no means facilitated, because meat being comparatively tough, the glands have to secrete an increased quantity in order to break down or disintegrate it, and there is, as I have observed, a greater drain on the system.

Vegetable or non-nitrogenous food contains potash; only those vegetables growing near the sea contain soda. The same reasons which apply to animal food hold good as regards vegetable, with this difference: the gluten, the legumen, and their other ingredients are acted upon by the gastric juice more rapidly, and that being the case, a less amount is required, and as a natural consequence less salt, or rather chloride of sodium, is abstracted from the blood; because the more the stomach is called upon to exert itself, a greater flow of blood to that viscus is the result, which takes place only when the food to be acted upon is of a harder or tougher material than ordinary, when the organ is filled to repletion, or when salt is omitted as a rule.