Читать книгу Foods and Their Adulteration - Harvey Washington Wiley - Страница 57

—The fallacy of the argument for small quantities is so evident that it needs only to be presented in brief form to show the intelligent and thinking people of this country the fallacy of the claims of experts in favor of chemical preservatives.

The arguments which have been advanced in excuse of the use of preservatives when used in minute quantities have, perhaps, been more vigorously urged for salicylic acid than for almost any other substance. This argument has been urged with such vigor and such ingenuity that a further reference may not be out of place here. The principle which is laid down is that a substance which is injurious to health when added to foods, if not a natural constituent thereof, or if not added for condimental purposes, does not lose its power of injury to health because it is diluted or given in small quantities. The only change which is made is to mask the injurious effects produced—to make them more difficult of ascertainment and impossible of measurement. The fallacy of the argument that small quantities of an injurious substance are not injurious may, perhaps, be best represented graphically. The accompanying chart (Fig. 7) shows theoretically the normal and lethal dose of a food and a drug or, as in this case, a chemical preservative. The chart shows two curves, one representing a chemical preservative and one representing a food. The normal dose of a food is that quantity of food which maintains a healthy adult body in equilibrium. It is represented in the chart on the right by the number 100. If the quantity of food necessary to maintain the equilibrium in a healthy adult body is slightly diminished, no apparent change is at first experienced and possibly even no discomfort. If, however, the quantity of food be still further diminished progressively, as indicated by following the curve down to the left, the point is finally reached when no food is given at all and death ensues, represented by 0 on the left hand of the diagram designated “Lethal dose.” As the curve begins to deviate from the perpendicular on the right the degree of injury is very readily noticed and starvation or symptoms of starvation are set up. Thus if you follow the perpendicular on the right downward to the point 80 the divergence of the corresponding point of the curve is already measurable. As you descend to 0 the magnitude of the measurement increases. It requires but very little further illustration to show how easily the effect of diminishing the normal dose of a food can be measured immediately after the curve begins to vary appreciably from the perpendicular on the right.

Fig. 7.—Graphic Chart Representing the Comparative Influences of Foods And Preservatives.

Let us now consider the perpendicular on the left, which is marked at the top under the term “Lethal dose,” namely, a quantity of the added preservative sufficient to destroy life. The normal dose of such an added chemical preservative is 0 and is shown at the base line to the right, marked “Normal dose.” If you add a very minute quantity of a chemical preservative, the curve representing it varies so slightly from the horizontal base as to be impossible of measurement by ordinary means. If we follow along to the number 75 on the horizontal base we see the deviation of the curve is sufficiently great to measure. At 50 it is still greater, at 25 still greater, while at the left of the basic line it is a maximum extending from 0 to 100, or the lethal dose. It is easy to show by mathematical data that no matter how small the quantity of an injurious substance or preservative it will still produce an injurious effect which may be infinitely small if the dose be infinitely small. It follows, then, as a mathematical demonstration that any quantity of an injurious substance added to a food product must of necessity be injurious, provided it is in the nature of a drug and the body is in a perfectly healthy, normal condition.

Hence the argument which has been so persistently urged in favor of a chemical preservative, that if in small quantities it is harmless, is shown to be wholly untenable. While there is no necessity for the addition of a harmful substance, where no particular benefit is secured thereby, and where there is no disturbance of the normal state of health, there can be no possible excuse of a valid nature to offer for the exhibition of even minute quantities. That these minute quantities would not be dangerous in so far as producing any fatal effect is concerned is conceded, but that in the end they do not produce an injury even in these small quantities is certainly to be denied. The course of safety, therefore, in all these cases is to guard the opening of the door. If the admission of small quantities is permitted, then there can never be any agreement among experts or others respecting the magnitude of the small quantity, and continued litigation and disagreement must follow. On the other hand, when the harmfulness of any substance which it is proposed to add to food is established and no reason for its use can be given other than the convenience, carelessness, or indifference of the manufacturer, the exclusion of such bodies entirely from food products follows as a logical sequence and a hygienic necessity.

The third method of preparing or preserving meat is by sterilization. Of all the various methods which have been proposed there is probably none which is, theoretically, so free of objections as the preservation of meat by sterilization, in other words, as canned meats. The only important thing is that the raw material used in canning must itself be meat free of disease, obtained under sanitary conditions, and subjected to sterilization before any fermentation or decay takes place. Pure, wholesome meat thus prepared and thoroughly sterilized will remain in an edible condition for a reasonable length of time. Unfortunately, as has been shown in the testimony respecting the packing industry of the country, canned meats have not always been selected solely for freedom from disease and for palatability. The question of diseased meat is discussed in another part of this book and, therefore, may not be taken up here. There have been used for canning purposes the fragments and, perhaps, inedible portions of carcasses, and this practice cannot be too severely condemned. This does not mean that these fragments and portions of carcasses are not fit for food, but they should be collected, prepared, and sold as such with plain notices to the consumers of their origin. A cheaper supply of beef would thus be furnished for those in humbler circumstances, and no imposition of any kind would be practiced because the nature of the meat would be fully understood.