There are indications in the customs of primitive peoples that "blood" and "salt" are recognized as in some sense interchangeable in their natures, qualities, and uses. And in this, as in many another matter, the trend of modern science seems to be in the line of primitive indications.

Peoples who have not salt available are accustomed to substitute for it fresh blood, as though the essential properties of salt were obtainable in this way. An observant medical scientist, writing of his travels in eastern Equatorial Africa, tells of the habit of the Masai people of drinking the warm blood fresh from the bullocks they kill; and this he characterizes as "a wise though repulsive" proceeding, "as the blood thus drunk provided the salts so necessary in human economy; for the Masai do not partake of any salt in its common form."[35]

Similarly, Dr. David Livingstone noted the fact that when he was among peoples who had difficulty in procuring salt, fresh-killed meat seemed to satisfy the natural craving for salt, while vegetable diet without salt caused indigestion.[36] In portions of China, also, where salt is not obtainable, or where it is too expensive for ordinary use, the blood of pigs or fowls is carefully preserved and eaten as if a substitute for salt.

Professor Bunge of Basel, who is quite an authority in the realm of physiological and pathological chemistry, speaking on the relation of salt and blood, says that "at every period, in every part of the world, and in every climate, there are people who use salt as well as those who do not. The people who take salt, though differing from each other in every other respect, are all characterized by a vegetable diet; in the same way, those who do not use any salt are all alike in taking animal food."

He says, moreover: "It is ... noteworthy that the people who live on an animal diet without salt, carefully avoid loss of blood when they slaughter the animals. This was told me by four different naturalists who have lived among flesh-eaters in various parts of northern Russia and Siberia. The Samoyedes, when dining off reindeer flesh, dip every mouthful in blood before eating it. The Esquimaux in Greenland are said to plug the wound as soon as they have killed a seal." Like testimony comes from India, Arabia, Africa, Australia, and various parts of America.[37]

The Jews of to-day, who are careful to drain the blood from slaughtered animals prepared for food, are accustomed to put salt freely on the meat thus drained. This is in accordance with the prescription of the Talmud, for the purpose of absorbing the blood not drawn out from the main bloodvessels. At the close of two hours from the slaughtering, the meat is washed for cooking. Whatever be the reason rendered for this application of salt, and its remaining on the flesh for a time, may there not thus be an instinctive supplying of the salts taken away by draining out the blood?

"Salt" and "salts" are terms often used interchangeably in the common mind. While they are distinct as employed by a scientist, it is not to be wondered at that they are confused by those who fail to note the differences; nor is it important to consider these differences in primitive thought and customs.

"A salt," as the chemists use the term, is a combination of an acid and a base. There are many salts in use in the world; among these the one best known and most widely used and valued is sodium chloride, or what is popularly known as "common salt." This has been used and prized, the world over, among all classes of men, from the earliest historic times.

Salt has long been popularly claimed as an important element of the liquids of the body, as shown in the blood, in the tears, and in the perspiration, of mankind. Later scientific experiments have confirmed ancient and traditional claims, that saline injections avail like blood transfusion for the preservation of life in an emergency.[38]

It has long been common among ordinary people to administer salt to one taken with a hemorrhage of the lungs, or stomach, or nose. This is the folk-lore remedy in many regions. Moreover, under careful medical and surgical direction it is now customary in the hospitals to keep on hand a warm solution of salt to inject into the veins or tissues of persons brought in sinking from a sudden loss of blood. Whatever connection the two ideas—the popular and the scientific—may or may not have, it is not to be wondered at that it has long been thought that, when blood has gone out from the body, salt might well go in.

Blood transfusion, by which the blood or life of a stronger or fresher person may permeate the being of a sinking one, has been known of for centuries, and there are at least traces of it in tradition from the earliest ages.[39] More recent experiments have shown that a saline solution is even safer and more efficacious than the warm blood from another life; now, therefore, this has largely taken the place of blood in supplying the waste occasioned by severe hemorrhages.[40] Various illustrations of this treatment are given as showing that when persons were in a very low condition through loss of blood, they have been rescued and restored through copious injections of a saline solution.[41]

The use of blood as food was forbidden to Noah and his sons after the Flood.[42] A tradition of the Turkish or Tatar nations says that Noah's son Japheth was their immediate ancestor, and that Toutug, or Toumuk, a grandson of Japheth, discovered salt as an article of diet by accidentally dropping a morsel of food on to salt earth, and thus becoming acquainted with the savor of salt.[43] This carries back the traditional discovery of salt to the age when blood was first forbidden as food.

It was long ago claimed by some that the red corpuscles of the blood are dependent for their color and vitality on the presence of salt, and recent scientific experiments and discussion have continued in the direction of the question thus raised.[44]

It has been shown by experiment that many of the lower animals, as well as man, are dependent for their life on salt in their blood. "When an animal is fed with a diet as far as possible free from salts, but otherwise sufficient, it dies of salts-hunger. The blood first loses inorganic material, then the organs. The total loss is very small in proportion to the quantity still retained in the body; but it is sufficient to cause the death of a pigeon in three weeks, and of a dog in six, with marked symptoms of muscular and nervous weakness."[45] A mode of torture in former ages is said to have been to deprive a person of salt, and cause him to waste away with painful salt-hunger. It is said that this mode of torture is still employed in China.

An Armenian story says that when a band of their people was in a stronghold of the mountains, and was besieged by the Turks, the latter failing to subdue the former by other means cut off the supply of salt from the Armenians, and this quickly subdued them.

In 1830, a paper by Dr. W. Stevens, read before the London College of Physicians, and afterwards elaborated and published in a volume, contended that the salient ingredients of the blood, "the chief of which is common culinary salt, ... is the cause of the red color, of the fluidity, and of the stimulating property, of the vital current." Dr. Stevens claimed that the poison of the rattlesnake, and various other poisons, operate directly on the blood, and produce disease or death "by interfering with the agency of the saline matter."[46]

"On the subject of the poison of the rattlesnake," Dr. Stevens, in this work, asserts that "when the muriate of soda (common salt) is immediately applied to the wound, it is a complete antidote. 'When an Indian,' he says, 'is bitten by a snake, he applies a ligature above the part, and scarifies the wound to the very bottom; he then stuffs it with common salt, and after this it soon heals, without producing any effect on the general system.'" In view of the fact that it might be objected that the salt is not the essential means of cure, but is an addition to the curative treatment, Dr. Stevens says that he has "seen a rabbit, that was under the influence of the rattlesnake poison, drink a saturated solution of muriate of soda with great avidity, and soon recover; while healthy rabbits would not taste one drop of the same strong saline water when it was put before them."

Dr. Stevens gives various illustrations, out of primitive customs, and in the experience of modern practitioners, of curative and prophylactic uses of salt in the treatment of fevers, where the condition of the blood seems to be a main source of evil. Aside from the question whether the claims of Dr. Stevens have been substantiated by later researches and experiments, his investigations and assertions are of interest as showing that, in the realm of modern science as of primitive practices, salt and blood have seemed to many to have interchangeable values.

If, indeed, this theory of Dr. Stevens, elaborated so carefully in the first third of the nineteenth century, in which he claims that salt practically represents blood, stood all by itself in the history of medicine, it would have less importance than it has in a formal treatise of this kind; yet even then it would show that such an idea had before now found a place in the human mind. But it by no means stands thus alone; a similar claim has been made both earlier and later.

Pliny, in his day, at the beginning of the Christian era, records it as the common belief that salt is foremost among human remedies for disease, and among preventives of sickness of all kinds.[47] He gives prominence to salt as a cure of leprosy,[48] whereas blood transfusion and blood bathing was the traditional treatment of that disorder.[49] Pliny also speaks of salt itself, and of salt fish in large quantities, as a supposed remedy for the bite of serpents,[50] this being in the line of asserted remedies among the Indians, according to Dr. Stevens. Various other disorders, especially of the blood, are named by Pliny as curable by salt.

Seventy years after the treatise of Dr. Stevens, a volume, recently published in London by C. Godfrey GÜmpel on "Common Salt,"[51] claims even more than Pliny, or any writer since his day, for "the vital importance of common salt for our whole physical and social life." He claims that of all the constituents of our life's blood "there is none which can possibly surpass common salt in its necessity for a strong healthy blood,"[52] and that both the red corpuscles and the white are largely dependent for their normal condition on "the presence of common salt in the system."[53]

A writer in the Asiatic Quarterly Review, not long ago declared that the government salt monopoly of the British Empire in India (since practically abolished, or modified) was a cause of greater evils than those resulting from either opium or alcohol. This claim is based on the idea that a lack of salt by the common people of India tends to a deterioration of blood and consequent loss of life. Asiatic cholera is said to be promoted by the lack of salt in the blood. Men and cattle alike are said to be sufferers from this cause, and the soil is rendered less fertile. Whether this idea is well grounded is a minor matter; that the idea has been in many minds is not to be questioned.

Thus it will be seen that in the primitive mind salt and blood have seemed to have common properties, and to be in a sense interchangeable, while the more careful observers in the world of science have rather grown toward this thought than away from it. Be it correct or incorrect, the human mind has never been able to rid itself of the idea.

Salt is sometimes used in the rite of blood brotherhood among primitive peoples, as is also wine, both wine and salt being counted the equivalent of blood, and the original and the substitute being sometimes employed together as if to intensify the symbolism. Stanley tells of the use of salt in this rite on the occasion of its performance with Ngalyema in the Congo region.[54] And so again in other cases.[55]

It is a common practice in the East to welcome an honored guest to one's house by sacrificing an animal at the doorway, and letting its blood pour out on the threshold, to be stepped over by the guest, as a mode of adoption, or of covenant-making.[56] When such a guest comes unexpectedly, and there is not time to obtain an animal for the welcoming sacrifice, it is customary to take salt and strew it in lieu of blood on the threshold,—salt being thus recognized as the equivalent, or as a representative, of blood.[57]

The measure of love and honor accorded to the welcomed guest is indicated by the cost or preciousness of the sacrifice on the threshold. There are traditions, at least, of the sacrifice of a son of the host in this way. Again a favorite horse has been thus sacrificed. More frequently it is a lamb that is the sacrifice. If there is no lamb available, a fowl or a pigeon is thus offered. The essential factor in every case is the blood, the life, outpoured. If, however, no actual blood is obtainable, salt, as representing blood, is accepted as indicating the love and the spirit which prompts the welcome, according to the giver's means. There could hardly be a fuller proof of the identity of salt and blood in the primitive mind.

When a Siamese student was asked by the writer whether the rite of blood-covenanting was known in his land, he replied: "There is no 'blood covenant' so far as I know. The custom is, if two persons are desirous to become firm friends or brothers they drink together salted water; then each takes an oath." He also suggested that he had heard that in former times they drank a fowl's blood in this rite.

Again, the mode of making a covenant of salt in some portions of the East coincides with this suggested identification of salt with blood in the primitive mind. In the Lebanon region, where the blood covenant, as a bond of union, is still recognized and practised,[58] the covenant of salt is also well known, not only as between new comers who are to enter into a mutual alliance, but as bringing into union friends who would be as one. In such cases a sword is taken, and salt is laid on its blade. The two friends in turn lick of the salt that is to unite them, as if they were tasting of common blood after the fashion of the "blood-lickers" in Mecca.[59]

Another illustration of this mode is given by Sir Frederick Henniker, in his notes of a journey in the East in 1819-20.[60] It was a shaykh of the Arabs who escorted him from Mt. Sinai northward, who cut this covenant with Sir Frederick. On the request being made for such an assurance of fidelity from the shaykh, "he immediately drew his sword," says Sir Frederick, "placed some salt upon the blade, and then put a portion of it into his mouth, and desired me to do the same; and 'Now, cousin,' said he, 'your life is as sacred as my own;' or, as he expressed himself, 'Son of my uncle, your head is upon my shoulders.'" Before this act the two were as cousins; now they were as one, the head of one being upon the shoulders of the other. The similarity of this rite with that of the blood covenant, in both its form and meaning, is obvious.

This correspondence of salt and blood in primitive thought, and in fact, will perhaps throw light on a disputed reference in a fragment of Ennius[61] to "salsus sanguis" (salted blood, or briny blood). It would seem that as the Jews held that the blood is the life, and the life is in the blood, similarly Greeks and Romans recognized the truth that salt is in the blood, and the blood is salt.

In the second century there were Christian ascetics who refused to take wine in the eucharist. Among these the Elkesaites and the Ebionites employed bread and salt instead of bread and wine. This seems to have been a recognition of the fact that salt, like wine, represented blood.[62]

Professor Hermann Collitz, of Bryn Mawr, has suggested, in this connection, that the very words, in Latin, for salt and blood, sal and sanguis, are from the same root.[63]

Certainly salt is sometimes used as a substitute for blood in primitive covenanting; on the other hand, blood is used for salt among some primitive peoples as an essential accompaniment of food. These facts being noticed by the author of this volume first suggested to him the real meaning of the covenant of salt.