BUFFALO MEDICAL JOURNAL.

VOL. LXIV.

JANUARY, 1909.

ORIGINAL COMMUNICATIONS.

No. 6

The Mineral Nutrients, Air, Water and the Salts.'

BY HENRY REED HOPKINS, M. D., Buffalo, N. Y.

Ninety-Seventh President of the Medical Society of the State of New York.

THE question of our daily bread is one of elemental import

ance, to the sick and to the well, in all classes and in all ages, for prevention and for cure. Its consideration may properly begin with a word of caution against the work of the optimist, the pessimist, the medical anarchist, and more than all others, because more numerous than all the rest, the over credulous, the brain weary, the pseudo-scientists, the Quimby-Eddyites. All of these are at once the enemy to be conquered, the heathen to be converted, the children to be won and protected, by sound teaching and right example upon our part.

In addition to its primary importance, the knowledge of dietetics is interesting from the fact that it is sought and used by all classes of doctors,-by physicians, by homeopaths, by eclectics, and by the osteopaths. The Quimby-Eddyites are the only medical cult of any considerable number that openly flaunt the importance of right ideas and practises in dietetics; on the other hand their predecessors and introducers, the homeopaths have won the most substantial of their confidence by strict attention to these matters. Furthermore, I think it is expedient at this time that we give this topic consideration for the reason that recent advances in physico-chemistry enable students to say in truth as never before that there is a science of dietetics, and the art of dietetics should ever be willing to receive with joy whatever of practical contributions science has to offer. And, finally, to conclude this introduction, the writer has something to say which he not only believes worthy of consideration and, moreover, for that something which he now offers he earnestly desires. the characteristic scrutiny and criticism from the members present without favor, and without mutual admiration, to the end that only the fit shall survive.

1. Read before the Medical Club, March 18, 1908.

For many years I have been troubled with the growing conviction that the role of the inorganic nutrients in animal metabolism is not adequately appreciated, at least as indicated by the teachings, the writings and the practice coming under my observation. I do not know of a writer on hygiene or dietetics who states this matter plainly and comprehensively with any approach to suitable emphasis, and of this part of medical literature generally it may be said, that it is feeble, confusing, uncertain, inadequate, incompetent. This criticism is competent only upon the assumption, the result of the best study and thought I have been able to give the matter, that the inorganic foods, the mineral nutrients, include air, water and the mineral salts found in the excretions and the bodies of animals. Also, the further assumption that when foods are classified and enumerated in the order of importance, the inorganic foods, the mineral nutrients, should stand in class one. That, as in the nutrition of plants the inorganic foods, the mineral nutrients are the foods and there are no others; even so in the metabolism of animals these same foods are far and away more essential and more important than any others; that in classification these should be placed first, and in description, these should be treated at length with the emphasis due their primary and singular importance. Perhaps it should be further observed here, that in thinking of classification of foods I am using the word in an inclusive and comprehensive sense, having in mind something of the relative importance of foods, of their intimate relation to life and to its manifestations, as sensation. growth, and repair, rather than having in mind the` more accidental appearances of foods, whether they are solid or fluid, bulky or concentrated, or the like. I am thinking of classification which is inclusive and which is at least an effort to recognise in some reasonable degree the present state of knowledge as to the physico-chemistry of biology.

Under the classification of foods by various authors: Parke's Hygiene gives: (1) Nitrogenous; (2) Fats and oils; (3) Sugars: (4) Water and salts, magnesium, calcium, potassium, sodium and iron as chlorides, phosphates and sulphates.

Currier Practical Hygiene gives: (1) Water; (2) Salts; (3) Albumins; (4) Fats and oils; (5) Starch and sugars.

Mrs. Hart in Diet in Sickness and Health says: Foods are divided into two classes: (1) Nitrogenous; (2) Non-nitrogenous, and being a woman adds a postscript: Inorganic water and salts.

Coplin and Bevan, in Practical Hygiene give: (1) Nitrogenous; (2) Fats and oils; (3) Starches and sugars; (4) Inorganic compounds, and adds to the latter that these demand no

comments.

Richards and Woodman, in Air, Water and Food, give: (1) Nitrogenous; (2) Fats and oils; (3) Starches and sugars; (4) Mineral salts.

Egbert, Hygiene and Sanitation, gives: (1) Proteids and albuminoids; (2) Carbohydrates; (3) Fats and oils; (4) Mineral salts.

Bergey, in Principles of Hygiene, makes no classifications of foods but recites constituents of the body inorganic and organic and then says: "All these various elements and chemical combinations constituting the composition of the body, must be supplied in the food supply in order that it may perform its normal functions and obtain energy for all of man's activities in life."

Stockton, in Personal Hygiene (Pyle), gives: (1) Nitrogenous substances: (2) Fats; (3) Carbohydrates; (4) Salts. Rohe in Textbook of Hygiene, gives: (1) Water; (2) Salts; (3) Proteids; (4) Fats or carbohydrates.

Wilson, in Handbook of Hygiene and Sanitary Science, gives: (1) Nitrogenous albuminates; (2) Fats or oils; (3) Sugars and starches; (4) Water and saline matters.

Harrington, in Practical Hygiene, gives: (1) Proteids; (2) Fats; (3) Carbohydrates and organic acids; (4) Water and mineral salts.

WHY AIR AND WATER ARE FOODS.

The facts which to my mind should compel us to include air and water in our list of foods, and should also give them a place at the head of that list, are found in a consideration of what are foods, what is a food? Let us listen to some definitions:

Friedenwald and Ruhräh says: "Food is matter that is taken into the body to supply nourishment, or to replace tissue waste." Bergey quotes Dr. Atwater's definition of food as follows: "Food is that which when taken into the body, builds up its tissues and keeps them in repair, or which is consumed in the body to yield energy in the form of heat to keep it warm and create strength for its work."

Hutchinson says "A food may be defined as anything which, when taken into the body, is capable of either repairing its waste or furnishing it with material from which to produce heat or nervous and muscular work." Harrington says: "Foods may be said to include everything taken into the system capable of being utilised directly or indirectly to build up normal structure, repair waste, or produce energy in any form."

Let it be noted that the descriptive terms of these definitions are distinctly inclusive in character. "That which;" anything which;" "everything taken into the system."

Again, it may be observed that the eminent writers are having in mind the essential fact that these food substances are

taken into the system, and they treat as immaterial and non-essential the route to that system, be that route by nose and lungs, or be it by mouth and stomach. The destination, the system is the thing, the route is not material.

Again, observe the inclusiveness of the phrase "capable of being utilised directly or indirectly." In these words the writer seems to have in mind a number of substances and chiefly some of the mineral salts which are incapable of oxidation, which pass into and through the system unchanged, and therefore a superficial examination might lead one to the conclusion that they could in no sense be considered foods; but upon more intimate study, it is learned that these substances are habitually found in living cells, that these substances are constantly given off from living cells, and that these substances must be constantly furnished as part of the food supply of living cells, and that therefore these substances should be included and rated as foods, hence the inclusive description "capable of being utilised directly or indirectly." It would seem that several tests or measurements are to be given any substance claiming to be a food. First, it must be some form of matter; second, it must enter the system; third, it must contribute directly or indirectly to the growth of cells or of the individual; fourth, it must aid directly or indirectly in the repair of waste; fifth, it must contribute directly or indirectly to the production of some form of vital energy.

With these tests or measurements in our minds, let us examine our substances.-air and water, and learn if their relations to metabolism are such as fit them for places in the list of foods. We will agree that air is matter, and that it is taken into the interior of the body through a complicated and specially devised mechanism whereby one of the constituents of the air is prepared for absorption into the system, and we will further agree that a certain proportion of each separate meal of air so taken into the body, so prepared for absorption, is absorbed and the residue is promptly extruded from the body after the manner of the excrements in general. We will probably further agree that the more important constituent of air,-oxygen,—which is absorbed directly into the system is utilised directly or indirectly to build up normal structure, repair waste, and to produce energy in every form. It possibly may help some of us to make this realisation more actual, more vivid, to recall that Thompson quotes Moss as authority for the statement, that the body of a man weighing 148 pounds contains 92.4 pounds of oxygen, about three times as much as the next in weight, the carbon which weighs 31.6 pounds.

When we further recall that oxygen is an essential constituent of every tissue, fluid and cell of the body, that it is found in all

of the excretions, that it is the active and energising agent in all of the chemico-metabolic reactions wherein and whereby vital energy is manifested, that when the supply of atmospheric oxygen is stopped for one minute, there is distress, for two minutes there is mortal anguish, and for three minutes there is the death of the individual, it would seem that we must conclude, not only is air food but also that air is the food.

The proof as to the right of water to be considered as an important food follows about the same lines as in the case of air, and in certain respects is more readily convincing. Many of us are dependent upon sight and smell and taste and touch in our recognition of matter, and although we may profess differently, the fact remains that it is easier for us to realise the materiality of water than it is of air. The contents of the bathtub, of the water jug, of the snow bank or of the swiftly flying snowball, or of the ponderous iceberg do not permit one to doubt that water is matter. I think all will admit that it would be quite a bit more difficult for us to reach such a conclusion if we knew of water only in its physical state of a pure gas, as found constantly present in the air. I refer to this for the reason that it seems to me quite probable that the failure of our masters and teachers to consider air as one of the foods comes in part from the unconscious reluctance to consider air as matter. Be this as it may the evidence in the case of water is easily convincing.

Neither do we need argument to convince us that water habitually enters the mouth and the system. The pleasures of the palate and that delightful something which comes to some of us after a few glasses of beer or of wine or of hot Scotch, remind us that water does enter the system and that frequently. The role of water as a factor in living matter is enormous but may be quickly stated. Water is the most abundant constituent of living matter, comprising all the way from 2 to 3 per cent. of the most dry of the tissues up to 95 per cent. or even higher of the blood and the lymph. Water serves a most important role in metabolism and growth, as an organising fluid for the colloidal matter, and as a solvent for the crystaloids, making a medium of exchange between the cells, the different tissues and organs, and the fluids of the body, serving most important uses in all metabolic processes. Water also aids directly as a nutritive substance. yielding its constituent elements for the construction of essential compounds of living matter. It further makes anabolism and katabolism possible by its action as the universal solvent, whereby all other foods are prepared for absorption for the penetration of cel membranes or walls in anabolism; and whereby all excretory substances are enabled to pass through those cell membranes