III. SOME FOOD-DANGERS, AND HOW TO AVOID THEM.
In connection with the subject of food and health, an important topic naturally intervenes in the course of such discussion, in the shape of the relation which impure foods bear to the production of illness and disease. Pure air and pure water are required by natural and common consent as necessities of existence; but the purity of the food we consume is no less a paramount condition of physical well-being. Food-impurities may be ranked under diverse heads. Adulteration of foods is thus a common cause of illness. The food, rendered of poor quality, does not contain the necessary amount of nutritious material; or it may impart disease from its being impregnated with matters foreign to its composition, and which have been added thereto for purposes of unfair trade-profit. For example, when one hears of alum and sulphate of copper being added to bread, it is evident that a serious form of adulteration is thus practised; while equally reprehensible modes of procedure are known to be in vogue when flour is treated so as to yield more than its legitimate quantity of bread; when rice, potatoes, and other starchy matters are added to the bread in the course of manufacture; or when flour of damaged or inferior quality is used. Similarly, when milk is adulterated with water, treacle, turmeric, and so forth, a cause of ill-health is clearly discovered. If tea be ‘faced’ with black-lead, or with Prussian-blue, turmeric, and China clay, there can be no question of the fraudulent and dangerous nature of such a practice; and when we read of preserved green peas being largely adulterated with sulphate of copper, and that a one-pound tin of green peas has been found to contain two and a half grains of this poisonous compound, it becomes evident that legislation directed against this worst of frauds—food-adulteration—is both necessary and highly requisite as an active feature of social law.
Into questions connected with the adulteration of food, we need not enter. Such topics necessarily belong to the sphere of the analytical chemist and of the sanitary inspector. Where adulteration is suspected, the wisest course for the public to pursue is carefully to note the place and date of purchase of the suspected article—full evidence on this head is necessary—and to supply the sanitary authorities of the town or district with a sample of the substance in question. This clue will be followed up independently by the authorities; and if adulteration be present, means will be taken to substantiate the charge and to prosecute offenders. There should be no leniency shown where cases of food-adulteration can be satisfactorily proved. Such practices form the worst of all frauds; they involve not merely commercial dishonesty, but include fraud against the health and well-being of the community and nation at large.
Other forms of food-impurity are well known, and demand attention from the public; inasmuch as, by the exercise of ordinary knowledge, many of these latter dangers to health may be avoided. Of impurities in water, we shall treat hereafter; hence nothing need be said at present regarding this class of food-dangers. Our milk-supply and our meat-supply, however, are matters over which every householder may and should exercise supervision. Special dangers attach, for example, to the incautious treatment of milk. If milk is suspected to be adulterated, or of poor quality, the determination of the error or fraud is a matter of scientific examination; and with regard to the detection of milk-dangers, arising from disease-contagion, the same remark holds good. It is indeed unfortunate that the first information we usually receive regarding a milk-supply which is thoroughly impure or hurtful, is derived from the effects of such diseased matter on the human frame. In this case, we are unfortunately able only to prevent the spread of an epidemic of disease—the prevention of the epidemic itself is impossible, save, indeed, by the vigilance of the dairyman or farmer in keeping the milk he sells free from all source of contamination. Epidemics of typhoid fever, for instance, are, as a rule, only made known by the occurrence of a series of cases in a given district. On being traced out, these cases are usually found to have been supplied with milk from one and the same source. When the surroundings of the dairy or farm are inspected, sewage-contamination is usually found. Leakage of drains into a water-supply is a common occurrence; and as this infected water is used in cleansing the milk-vessels, the origin of the epidemic is clearly enough accounted for. In some cases, dairies have been found to be constructed in a thoroughly insanitary manner, and cleanliness—the first condition where milk is concerned—is by no means always observed. The remedy for these errors and negligences in connection with this all-important article of diet, lies in one direction only—namely, a system of rigid and continuous dairy inspection. Such inspection is never complained of by those tradesmen who take a pride in their occupation, and who endeavour, by ordinary attention to business, to secure the purity of the milk they sell. It might be added also, that if other articles of food are duly liable to official examination, and if the articles sold by grocer and butcher are duly supervised and examined, there is no reason why the premises of the dairyman should not be similarly inspected. We do not, as a rule, contract serious illness from impure coffee, or even from a poor quality of butcher-meat; but a dirty dairy and an infected milk-supply may, in a single day, sow the germs of a fever which may prostrate a village or community, and entail all the misery and hardship which serious illness inevitably carries in its train.
The domestic care of milk is a second topic to which the attention of the householder should be directed. It cannot be too clearly borne in mind that milk, of all fluids, is singularly apt to absorb deleterious matters. Sewage-emanations and other gases, paint, metallic matters, &c., are all readily taken up by milk. Hence the absolute necessity for seeing that when milk is received into our homes, it is stored in a safe and sanitary position. Milk should never be stored in metallic vessels in the first place; and it should not be kept in cupboards or other receptacles which are situated in the neighbourhood of sinks, closets, or open drains. Too frequently, such carelessness in the home-treatment of the milk-supply leads to illness, which is all the more serious, because its origin is unsuspected.
With regard to the liability of milk, taken from cows suffering from various diseases, to produce illness in man, many and varied opinions exist. A general rule, and one in the observance of which great safety exists, is, that milk from an animal in any way affected with disease should never be sold to the public. Where uncertainty exists, it is a matter of sheer common-sense to err on the safe side, and to incur no risk whatever. It is only fair to add, that milk from cows suffering from ‘foot-and-mouth’ disease has been consumed in many cases without injury resulting. But opposed to this fact, we find cases in which the use of such milk has been followed by throat-ailments and other troubles in man. The milk of over-driven cows—‘heated milk,’ as it is called—has been known to produce colic and diarrhœa in children. It is also probable that while some persons in robust health may escape, others are liable to be affected by milk taken from diseased animals. Pigs to which the milk of cows, ill with ‘foot-and-mouth’ disease, has been given, are seized with that disease in a few hours. The safe rule, therefore, appears to be that already mentioned. If a cow is affected with any disorder or disease, the milk of the animal should not be consumed by man. Only by attention to this rule can outbreaks of disease in man be avoided, and the public safety fully secured.
The flesh of animals is liable to acquire under certain conditions diseased properties. Hence, it is necessary that we should be on our guard against such sources of illness. Thus, certain fevers to which pigs, sheep, and cattle are subject render their flesh unfit for human food; and there are certain parasites inhabiting the flesh of fish which may also be productive of disease when the meat in question has been eaten by man.
Good meat in a fresh state should be firm and elastic to the touch. The characteristic odour of fresh meat should be present, and the meat-tissue should be dry, or at the most merely moist. The appearance of good meat is marbled, and its action on blue litmus-paper is acid—that is, it turns the blue paper to a red colour. Bad meat, on the other hand, is usually extremely moist, or even wet; it has a sodden feel, and the presence of dark spots in the fat is a suspicious sign. The marrow of the bones, instead of being light red in colour, as in fresh meat, is brown-tinted, and often shows black spots. Tested by litmus-paper, bad meat is either neutral or alkaline, and turns red litmus-paper to blue, or does not alter either red or blue test papers. The odour of bad meat is highly distinctive; and its colour, as a rule, is suspiciously dark.
Regarding those animal-diseases which are believed to unfit the flesh for human use, considerable diversity of opinion exists. For example, the flesh of animals suffering from pleuro-pneumonia is regarded, almost universally, as unfit for consumption; although opinions exist which regard such flesh as harmless. Here, as in the case of milk, already alluded to, it is probable diversity of opinion arises from the different conditions under which the results of eating such flesh have been studied. In some cases, it is true, no evil results have accrued from this practice; Loiset showing that during nineteen years, at least eighteen thousand oxen suffering from pleuro-pneumonia were killed and used in Lyons, as food, without any known evil results. But it should be remembered that the disease has its advanced as well as its initial stages; and in any case the opinions expressed with regard to the harmless character of the flesh, can only apply to cases in which the animals have been killed in an early phase of the disorder. The disease known as ‘braxy’ in sheep presents a similar conflict of opinions. Over fifty per cent. of young sheep in Scotland are stated by Mr Cowan in his Essay (1863) to perish from this disease. The disorder is a fever, attended by very characteristic symptoms; but ‘braxy mutton’ is eaten nevertheless by Scottish shepherds with impunity—although an important precaution is observed in this case by steeping the mutton in brine for six or eight weeks, and then drying it. The chief danger which appears to arise in man from the use of diseased meat is the development of blood-disorders and of blood-poisoning. ‘Carbuncular disease’ has increased in Scotland since 1842, when pleuro-pneumonia first appeared; and this affection has apparently increased since lung-diseases in animals have become common. On the whole, then, it may be urged that even with opinions of weight which allege the harmless character, in certain cases, of the flesh of diseased animals, there are risks involved which make the rule, that meat under such circumstances should be rejected, a highly safe and commendable practice both for public and trade attention.
In the case of the parasites which may affect meat under certain circumstances, there is fortunately no diversity of opinion to be encountered. The question of ‘braxy mutton’ may be debatable; in that of meat infested with parasites, no argument is permissible. All parasitic animals are liable to induce disease of more or less serious character in man; hence, if meat can be proved to be so infested, it should be summarily rejected.
The most common parasites which man is liable to acquire from flesh of various kinds are certainly tapeworms, which have been frequently described, and the dangers from which are well known. More serious in its nature is the Trichina spiralis, a minute worm, found chiefly in the muscles of the pig. This worm, if eaten by man with pork, develops with great rapidity within the human digestive system, and produces enormous numbers of young, which, boring their way through the tissues to the muscles of the patient, cause serious and often fatal illness. Once in the muscles, no further change ensues to the worms, which simply degenerate into mere specks of lime. It is this trichina which produces the disease known as trichinosis. Fatal epidemics of this disease are not uncommon on the continent, especially where the unsanitary practice of eating uncooked or dried sausages is greatly in vogue.
Regarding the prevention of the diseases caused by parasites, one stringent rule should be invariably kept in mind—namely, that all flesh-meat should be thoroughly cooked before it is consumed. The practice of eating underdone meat and smoked provisions is attended with great danger. A degree of heat sufficient to cook meat thoroughly, may, as a rule, be trusted to destroy parasitic life which the flesh may contain—although, of course, no one would sanction the employment as food of any meat known to be parasitically infested. To this necessary precaution may be added the advice, that drinking-water should never be taken from ponds, lakes, canals, or rivers in which vegetable matter grows freely, as such water is liable to contain parasitic germs; and all vegetables used for food, and especially those used raw—as in the case of salads—should be thoroughly washed before use. Our dogs being liable to harbour certain forms of internal parasites highly injurious to man, should also have their health and feeding inspected and supervised. And it may be lastly mentioned, by way of encouragement in sanitary reform, and in the care and selection of our flesh-foods, that as far back as the reign of Henry III. the desirability of securing meat free from parasites was clearly known. In the reign of that monarch, butchers who were convicted of selling ‘measly pork’ were sentenced to exposure in the pillory as a punishment for their misdeeds.