Aside from the inherent ingredients of food and drink, which arc discussed in Chapter XV (Important Constituents Of Food Stuffs Aside From Protein, Fat And Carbohydrate, Salines And Purins. Medicinal And Toxic Ingredients Of Edible Substances), and substances developing through the action of bacteria upon organic matter, toxic substances may occur adventitiously.

According to local geologic conditions, various mineral poisons may occur in water or even in plants and hence, indirectlv, in the flesh of animals. Poisoning of this kind is nearly limited to lead, arsenic, antimony, copper, tin, zinc and certain salts, as nitre. The presence of enough of these poisons to contaminate water and plants to any physiologically appreciable degree, is, on the whole, rare and confined within narrow geographic bounds. In the aggregate, it is not so important as the deleterious action of water highly charged with lime or alkali.

Poisoning from containers is not so frequent as formerly. Water running through lead pipes may produce chronic! lead poisoning. Hard water soon deposits a coating which prevents the solution of lead to any appreciable degree. The softer the water, the more carbon dioxid it contains and the higher its temperature, the more likelihood is there of lead poisoning from pipes. In any circumstance conducing to lead poisoning, sulphates or sulphuric acid lemonade - with due attention to the teeth - should be employed as a routine prophylactic.

Pewter and brass dishes are very likely to produce mineral poisoning, especially if used to contain acid foods and leverages or those in which acidity may be produced by fermentation. It is, at present, rare. Lead poisoning may also occur from the use of cheap "tin" ware or solder; so also may other minerals be present. Provided that pure tin and solder free from lead, arsenic, etc., is used and that the contents of cans are not acid, there is very little danger from the use of canned goods. Zinc and tin poisoning are, however, occasionally reported but the rarity of such reports and the marked severity of the symptoms in certain groups of cases, suggest an error in diagnosis.

Preservatives, such as salicylic and boric acid, hyposulphites, formic aldehyde, etc., rarely produce acute poisoning but their prolonged use produces fibrosis of the blood vessels and viscera, especially the kidneys.

Adulteration and sophistication are of widely different forms: 1. The more or less complete substitution of a perfectly harmless and equally or nearly equally valuable nutrient, as glucose for cane sugar; fat for butter in oleomargarine; cereal meals, etc., for chocolate or coffee; acetic and citric acid for vinegar and the natural juice of lemon, cotton-seed or peanut oil for olive oil etc.; or the analogous substitution of a cheaper for a more expensive grade of food stuff, of vanillin or other active principles prepared synthetically or from cheaper natural sources, instead of from the regular source; or the substitution of a wine, tobacco etc., from a miscellaneous source, for a brand supposed to come from a distinct locality. Such frauds are of no hygienic importance.

2. The use of fillers of various kinds, but not distinctly toxic or injurious; as lard in cheese, corn starch in ice cream, terra alba, kaolin etc., in candy, paraffin in gum, glucose in honey, flour in spices etc.

3. The use of various pigments. In so far as these are harmless, there is no particular objection to their use. Butter is frequently colored with carrot or anatto; peas, beans etc. with chlorophyl, which is even cheaper than copper, although the latter, in the small quantities used, is not especially dangerous. Synthetic aniline dyes are used to color candy frosting etc. and, for the most part, do no harm. Chrome yellow is a dangerous pigment for whose use there is no excuse.

Under present conditions, the adulteration of food stuffs is not very prevalent, except in physiologically innocent forms. Sugar is almost 100% pure, a slight trace of blue pigment, being added to kill the natural yellow tinge, to which latter there is no sound objection. Even powdered sugar is usually free from starch. So long as maple syrup and honey taste like the natural product and are rich in sugar and free from toxic ingredients, it is of no practical disadvantage that most of the saccharose of the former is derived from sugar cane or beets, for the sugar is identical with that of the maple; nor that the honey comb is pressed out of paraffine nor that the bee, instead of extracting the sugar from flowers, carries it from a convenient pan of glucose nor even that a man instead of a bee fills the comb.

In many cases, it is difficult to decide how far a name of a food should be used literally. If butter crackers really contained butter they would not be so well flavored; no one expects a marsh mallow drop to be made of marsh mallows; the average purchaser would feel that he had been cheated if he was given genuine iceland moss gum, not flavored with anise, instead of a plain sugar candy with this flavor. Paraffine answers the purpose of a chewing gum quite as well as any vegetable gum and, in so elaborate preparations as confections, any pigment, flavor, or base which is harmless and which does not detract from the sapid qualities, is permissible. It is easy for a manufacturer or dealer to apply the same line of argument to various other articles of diet. However, the following points should be and, for the most part, are insisted on by health authorities, with fairly efficient enforcement:

1. Any poisonous substance or any which may reasonably be considered to be probably poisonous, should be interdicted;

2. The trade name and label should indicate the true nature and source of an article so that if a cheaper substitute - although of equal practical value - is offered, it should be purchasable at a cheaper price. For instance, there is no reason why pea nut or cotton seed oil should not be used in place of olive oil and, equally, no reason, why the dealer should be paid the price of olive oil. In some instances, it is very easy, in others very difficult to determine how far a trade-name should be construed literally. A Boston cracker need not be made in Boston and a soda cracker made in Boston is not a Boston cracker in the dietetic sense. It is more difficult to decide whether Swiss cheese should mean the imported article, or whether it applies to any cheese in which gas bubbles have formed under the action of the colon bacillus or merely to any fairly tough cheese that is markedly porous.

3. A food stuff that is commonly used as an article of nourishment, should not only be free from harmful ingredients but should contain the ordinary natural or commercial ingredients, in standard amounts and proportions, subject to unpreventable natural or commercial variation.

4. A food stuff - for example, candy - that is not ordinarily used as a source of nourishment and that is avowedly of complex and artificial composition, may contain any ingredient that is not harmful and that does not render it unpalatable or that does not depart too far from the ordinary composition.