Sometimes the foods have not advanced to a stage in which the poisonous products are manifested; but in the intestinal canal the germs contained in these foods manufacture toxins which are readily absorbed and produce the severe disturbances noted in cases of ptomain poisoning.
The liver, which has been styled the “watchdog of the body,” has a special power to destroy many of the toxins contained in the food material passing through it, and it is due to this fact that many deleterious substances, taken with the food, are neutralized and their poisons rendered harmless to the system. When the liver is disordered, this important function may be hindered, or cease to be active. Therefore, the importance may be readily seen of keeping the liver in a vigorous condition by means of exercises which will send an active circulation through it and keep the nerves controlling it in perfect functioning order.
Ptomain poisoning results most often from tainted meat, milk, and fish. Putrefactive processes may have begun in meat, which is thus rendered “high,” but if it is thoroughly cooked the poisons may be made inert. Many enjoy the flavor of such meat. The Eskimos, as is well known, will cache a seal or other animal against a time when food is less plentiful and after months, perhaps, will eat it with relish and without harm, though it cannot be touched by people with less hearty appetites. Old eggs, eaten as a luxury by the Chinese, and the fermented fish used by other races are familiar examples of tainted foods.
The sale of “bob” veal, or the flesh of very young calves, has been prohibited because in many people its ready decomposition causes active diarrhea.
The process of smoking various meats affects materially only the outside portion, the inner may furnish a suitable bed for the development of germs. Great care should be exercised and thorough inspection made of any meat which is eaten raw, as dried beef, or any pork product.
Ice-cream, as made in the home, is usually innocuous, but when it is made in factories, unless care is exercised to keep containers clean and sterilized, the cream or milk may become infected from careless handling, either before or after it reaches the factory—particularly in warm weather. Toxins which cause serious and often fatal poisoning develop. Many such cases have resulted from the free eating of infected ice-cream at picnics or other social gatherings.
One should guard against overripe cheese, though cheese of any kind acts as a poison with some people. Cases of severe intestinal disturbance may occur in those who are unable to eat certain articles of food, as strawberries, lobsters, or oysters; these attacks should be carefully distinguished from cases of true poisoning.
Sometimes, however, particularly in the case of fish or oysters which have been frozen, unless they are eaten immediately after they have been thawed, toxins develop which cause severe constitutional disturbance, particularly of the nervous system. These toxins do not seem to affect the gastro-intestinal tract so markedly. Infected shellfish, particularly mussels, have caused death in two hours by their effect on the nervous system.
Many fish after being smoked are eaten raw, and if the ptomains have begun to develop, poisoning follows.
Care must be taken in purchasing fish for the table that the flesh is firm and the odor absolutely without taint.