Sir James George Frazer (18541941). The Golden Bough. 1922.
food which a man has in his stomach and the refuse of it which he has left untouched, and hence by injuring the refuse you can simultaneously injure the eater. Among the Narrinyeri of South Australia every adult is constantly on the look-out for bones of beasts, birds, or fish, of which the flesh has been eaten by somebody, in order to construct a deadly charm out of them. Every one is therefore careful to burn the bones of the animals which he has eaten, lest they should fall into the hands of a sorcerer. Too often, however, the sorcerer succeeds in getting hold of such a bone, and when he does so he believes that he has the power of life and death over the man, woman, or child who ate the flesh of the animal. To put the charm in operation he makes a paste of red ochre and fish oil, inserts in it the eye of a cod and a small piece of the flesh of a corpse, and having rolled the compound into a ball sticks it on the top of the bone. After being left for some time in the bosom of a dead body, in order that it may derive a deadly potency by contact with corruption, the magical implement is set up in the ground near the fire, and as the ball melts, so the person against whom the charm is directed wastes with disease; if the ball is melted quite away, the victim will die. When the bewitched man learns of the spell that is being cast upon him, he endeavours to buy the bone from the sorcerer, and if he obtains it he breaks the charm by throwing the bone into a river or lake. In Tana, one of the New Hebrides, people bury or throw into the sea the leavings of their food, lest these should fall into the hands of the disease-makers. For if a disease-maker finds the remnants of a meal, say the skin of a banana, he picks it up and burns it slowly in the fire. As it burns, the person who ate the banana falls ill and sends to the disease-maker, offering him presents if he will stop burning the banana skin. In New Guinea the natives take the utmost care to destroy or conceal the husks and other remains of their food, lest these should be found by their enemies and used by them for the injury or destruction of the eaters. Hence they burn their leavings, throw them into the sea, or otherwise put them out of harms way.
From a like fear, no doubt, of sorcery, no one may touch the food which the king of Loango leaves upon his plate; it is buried in a hole in the ground. And no one may drink out of the kings vessel. In antiquity the Romans used immediately to break the shells of eggs and of snails which they had eaten, in order to prevent enemies from making magic with them. The common practice, still observed among us, of breaking egg-shells after the eggs have been eaten may very well have originated in the same superstition.
The superstitious fear of the magic that may be wrought on a man through the leavings of his food has had the beneficial effect of inducing many savages to destroy refuse which, if left to rot, might through its corruption have proved a real, not a merely imaginary, source of disease and death. Nor is it only the sanitary condition of a tribe which has benefited by this superstition; curiously enough the same baseless dread, the same false notion of causation, has indirectly strengthened the moral bonds of hospitality, honour, and good faith among men