The remedy is obvious and has been frequently suggested--namely, laws prohibiting the addition of any chemical to food except in certain definitely specified cases. The presumption then would be--as in truth it is--that such chemicals are more or less dangerous, and proof of innocuousness must be brought forward before any one substance can be listed as an exception to the general rule. Such laws would include not only the use of chemicals or preservatives, but the employment of substances to "improve the appearance" of foodstuffs. As already pointed out, the childish practice of artificially coloring foods involves waste and sometimes danger. It rests on no deep-seated human need; food that is natural and untampered with may be made the fashion just as easily as the color and cut of clothing are altered by the fashion-monger. The incorporation of any chemical substance into food for preservative or cosmetic purposes could wisely be subject to a general prohibition, and the necessary list of exceptions (substances such as sugar and salt) should be passed on by a national board of experts or by some authoritative organization like the American Public Health Association. FOOD SUBSTITUTES On grounds of economy or convenience familiar and natural articles of food are sometimes replaced or supplemented by artificial chemical products, or by substances whose food value is not so definitely established. I need refer only briefly to those notorious instances of adulteration in which chicory is added to coffee, or ground olive stones to pepper, or glucose to candy. On hygienic grounds alone some such practices are not open to criticism, however fraudulent they may be from the standpoint of public morals. It might be argued with some plausibility that chicory is not so likely to harm the human organism as caffeine and that sprinklings of ground cocoanut shell are more wholesome than pepper. But there is another group of cases in which the artificial substitute is strictly objectionable. The use of the coal-tar product saccharin for sweetening purposes is an example. This substance, whose sweetening power is five hundred times as great as that of cane sugar, has no nutritive value in the quantities in which it would be consumed, and in not very large quantities (over 0.3 gram per day) is likely to induce disturbance of digestion. As a substitute for sugar in ordinary foodstuffs it is undesirable.[48] The use of cheap chemically prepared flavors such as "fruit ethers" in "soft drinks," fruit syrups, and the like in place of the more expensive natural fruit extracts affords another well-known instance of substitution. Probably more important hygienically is the production of "foam" in "soda water" by saponin, a substance known to be injurious for red blood corpuscles.