Salt and the salt industry

by Albert Frederick Calvert

CHAPTER II
THE BEGINNINGS OF THE SALT INDUSTRY

Salt, being existent in all animal and vegetable life, is coeval with life itself; it was present in the first herbage which gave nourishment to the first beast that, in its turn, became food for the first omnivorous man. In the beginning, man consumed the saline essences that were required to preserve his body in health, in the form of sodium chloride, which he absorbed in the uncooked flesh of animals, birds, and fishes, and in raw green-foods. The herbivorous animals were equally dependent upon salt, and, finding it in only infinitesimal quantities in the grasses upon which they fed, instinct directed them to the sea swamp pasturage and to the outcropping salt deposits. So long as man’s diet consisted of uncooked foods, his fresh meat provided him with a sufficiency of salt, but directly he employed a cook-pot in the preparation of his food, the boiling processes denuded it of 70 per cent. of its natural salt, and it became necessary for him to make up the deficiency. It must have been at this period that his herds directed his attention to the “salt licks” from which they satisfied their own saline wants, and enabled him to secure salt as a distinct and separate condiment.

It is probable that, from the Palaeolithic Age down to the time of the early Roman writers, man was content to season his victuals by the simple process of licking a piece of rock-salt, and we have no record to indicate the period when salt was first employed in the cooking of food. From varieties of grain and fragments of pottery that have been discovered in the dwellings of the cave-men of Belgium, it is supposed that salt was employed in the cooking of wheat and barley some five thousand years ago. Thirteen centuries before Christ, fish preserved in salt was eaten in Ancient Troy, and, according to Herodotus, the Egyptians not only salted ducks, quails, and a species of sardine which inhabited the Nile, but also employed salt or brine as an antiseptic in preparing the bodies of the illustrious dead for the process of embalming.

We cannot determine the period in which salt came to be regarded as a symbol of sanctity or entered into the religious ceremonials of the ancients. We know that in the Levitical Law, promulgated in 1500 B.C., every meat-offering was seasoned with salt, and salt is referred to in the “Verbal Instructions” which were enunciated by the founder of Buddhism, five centuries later. By the time of Pythagoras, about 600 B.C., salt was regarded as the emblem of justice, but who shall say when the Arabs first employed it as a token of friendship, or the Chinese offered their first oblation to Phelo, the salt deity of Celestial worship? We read in Herodotus that caravans brought salt from North Africa, and Schleiden tells us that the priests of Egypt preferred the salt of Hammomen to that evaporated from sea-water; but these references do not help us to fix the date when salt became an article of commerce, or tell us when or where or by whom it was first produced in a manufactured form. It was rock-salt which the Egyptians procured from the salt basin of the Sahara, and rock-salt from the margin of the Red Sea was the variety that is referred to by the compilers of Biblical history. But, although the natural crude product was probably the sole form in which it was known in the Western world by the Ancients, and through the vaunted golden epochs of Babylon, Byzantium, and Greece, the Chinese—who had invented explosives before the Romans had perfected the catapult, and had learnt to navigate by the compass while yet the mariners of the Mediterranean were dependent upon the stars and their wits—had probably been familiar for ages with a salt manufactured by a process, the origin of which they had forgotten, but the practice of which was to remain in operation, almost without revision, for further thousands of years.

The first mention of salt in the Chinese language is found in the annals of the Emperor Yu (2205–2197 B.C.), who ordered the province of Shantung to supply the Court with that commodity. During the Chow dynasty (1122–249 B.C.) the administration of the salt industry was conducted by Court officials, but the Crown monopoly of salt was not instituted until the days of Kuan Chung, who died 645 B.C. Between A.D. 561 and A.D. 583, references to various taxes on salt lead us to the conclusion that salt was produced at that period from sea-water, salt marshes, and salt springs, and at the present day salt is produced in China in three varieties—sea-salt, lake-salt, and well-salt. As the success of the boiling operation (which antedated by unnumbered centuries the comparatively modern industry of extracting salt from sea-water by evaporation in the sun) depends mainly on the condition of the brine and the time allowed in each stage of the process, the details were the subject of many series of experiments in the pursuit of the perfect system, but since about the twelfth century the following method has been consistently followed by the Chinese salt-makers. The whole of the sea-shore in the neighbourhood of the salt works is measured out and divided into a number of small, regular squares; the surface layer in each is dug out; the bottom of each pit thus formed is then strewn with straw, and the earth that has been removed is thrown back upon it. When these brine ovens, as they were called—which are shaped like chests, 9 ft. long, 2 ft. broad, and 3 ft. deep—are prepared, they are soaked with sea-water. The sea-water in the interior of the ovens forms brine, and flows through little ditches into wells which have been dug for its reception. From these wells, which are about 8 ft. deep, the brine is drawn out and carried to the boiling ovens. These brine ovens are furnished with large evaporating pans, three to five of which are attached to each oven. The boiling takes place at once and is continued without interruption, from 11 p.m. until 10.30 on the following morning, and during this period the salt is taken out six times. As soon as the salt begins to harden, pods of the tsao-chio tree are thrown into the pans, in order that the particles of salt may combine more quickly, and as soon as it is precipitated, it is removed and the pans are refilled with fresh brine. On an average, 600 cathés of the best brine yield 140 cathés of pure salt, which is produced in three qualities and colours—white, dark, and yellow. The white is the best, the dark is less esteemed, and the yellow, which is much inferior, has a bitter taste.

Since the fifteenth century, the Chinese have produced salt by solar evaporation of salt water, according to a simple but satisfactory process. Pits are dug on the sea-shore and bamboos are laid crosswise over them. The whole is covered with double mats, and sand is strewn over the top. Every morning and evening the covering of sand is soaked with sea-water by the tide, and the salt liquor finds its way into the pits. As soon as the water has receded, the salt workers appear with flaming bundles of straw, to test the saline character of the moisture, which is not regarded as fully impregnated unless the salt vapour arising from the pits extinguishes the fire. The brine thus produced is drawn off and run into secondary or crystallizing ponds, the level of which is set a foot or so below the first series of pits. The secondary ponds, which are smaller and of less depth, are provided with carefully-rolled, hard clay bottoms. When a sufficiently thick crystalline deposit has been formed at the bottom of the secondary ponds, workmen, starting at the centre, scrape the bottoms, working outward spirally and finishing at the corner of the pond, where the coarse crystalline product is collected and allowed to drain. When drained and dried, the salt is ready for transfer to the market.

In Japan, where the manufacture of sea-salt by boiling or by spontaneous evaporation was introduced more than two thousand years ago, the process is similar to that employed in China, but in some parts of the kingdom the evaporation basin generally employed in solar evaporation is dispensed with. In the latter method, a level field is formed close to the sea and sprinkled over with fine sand. Sea-water is then poured into the field, and, after evaporation of the water, the salt crystallizes and adheres to the sand. The mixture of salt and sand is next thrown into a kind of extracting apparatus and sea-water is poured upon it, whereupon the salt is dissolved and filtered in the form of a thick salt liquid. In other Japanese salt fields the concentrated liquor is poured into a crystallization basin prepared for the purpose, and, upon evaporation of the water by the sun’s heat, the salt crystallizes.

ANCIENT SALT WORKS

A. Wooden Ladle. B. Cask. C. Tub. D. The Master. E. Assistant. F. The Master’s Wife. G. Wooden Spade. H. Boards. I. Salt-baskets. K. Hoe. L. Rake. M. Straw. N. Bowls. O. Bucket for Blood. P. Beer Tankard.