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.
Among the many other familiar examples of food substitution, sophistication, and adulteration there are some of demonstrable hygienic disadvantage and others whose chief demerit lies in simple deception. Of practically all it may be said that they are indefensible from the standpoint of public policy since they are based on the intent to make foodstuffs appear other than what they really are.
It is the opinion of some who have closely followed the course of food adulteration that, while the amount of general sophistication—legally permissible and otherwise—has greatly increased in recent years, the proportion of really injurious adulteration has fallen off. Be that as it may, it is plain that the opportunity for wholesale experimentation with new substances should not be allowed to rest without control in the hands of manufacturers and dealers largely impelled by commercial motives. So long as the motive of gain is allowed free scope, so long will a small minority of unscrupulous persons add cheap, inferior, and sometimes dangerous ingredients to foodstuffs. The net of restriction must be drawn tighter and tighter. The motives leading to the tampering with food fall mainly under three heads: (1) a desire to preserve food from spoiling or deterioration; (2) a puerile fancy—often skilfully fostered for mercenary reasons—for a conventional appearance, as for polished rice, bleached flour, and grass-green peas; and (3) intent to make the less valuable appear more valuable—deliberate fraud. Only the first-named motive can claim any legitimate justification, and its gratification by the use of chemical preservatives is surrounded with hygienic difficulties and uncertainty, as already set forth. From the unbiased view of human physiology the dangers of slow poisoning from chemically treated foods must be regarded as no less real because they are insidious and not easily traced.
CHAPTER V
FOOD-BORNE PATHOGENIC BACTERIA
Many cases of so-called food poisoning are due to the presence of pathogenic bacteria in the food. In some instances, as in the typical meat poisoning epidemics, symptoms develop so soon after eating that the particular food involved is immediately suspected and laid hands on. In other cases the guilty article of food is difficult to trace. Certain cases of tuberculosis are undoubtedly caused by swallowing tubercle bacilli in the food, but the precise source and date of infection can be rarely, if ever, certainly established.
The presence of pathogenic bacteria in food is usually due either to the contamination of the food by infected human beings during the process of preparation or serving, or to an infection of the animal from which the food is derived. The relative importance of these two factors is quite different in the various infections.
TYPHOID FOOD INFECTION
The typhoid bacillus does not attack any of the domestic animals; consequently all food-borne typhoid is caused more or less directly by human contamination. A remarkable instance of typhoid infection due to food was reported in 1914 in Hanford, California, where ninety-three typhoid cases were caused by eating Spanish spaghetti served at a public dinner.[49] Investigation showed that this dish was prepared by a woman typhoid-carrier who was harboring living typhoid bacilli at the time she mixed the sauce for the spaghetti before baking. Further laboratory experiments indicated that the ordinary baking temperature at which the spaghetti was cooked was not only not sufficient to sterilize the food, but afforded a favorable opportunity for the bacteria in the interior of the mass to multiply. The infection of the food was consequently heavy and involved a very large proportion (57 per cent) of those present at the dinner.