Salt is a mineral that was in great demand particularly with the beginning of an agricultural mode of life. Hunters and food-gatherers probably obtained a large amount of their salt intake from the animals they hunted and from fresh plant food.
Salt only becomes an essential additive where fresh foods are unobtainable in very dry areas, where body perspiration is also normally excessive. It becomes extremely desirable, however, amongst societies with relatively restricted diets as was the case with arable agriculturalists. We have no idea when the salt resources of the Sahara at Taghaza and Awlil were first extracted. That they were an element in the trade of the Sahara by the first millennium of our era is evident from Arabic texts of the last quarter of the millennium. It is probable that some of the salt extraction is as old as the copper-mining and the development of the Tichitt settlements in Mauretania, both areas where a sedentary life would have imposed the need for salt supplies. W e know quite a lot about mining
activities in the medieval period, which will be discussed in later volumes, but nothing about them at this time. It is probable that at this period the mining operations were of a fairly simple kind. Salt would have been available as a surface deposit in various parts of the Sahara as a result of the desiccation process after — 250. Perhaps man noted which
dried-up lakes, swamp or pond beds attracted wild animals. Surface salts are often quite obvious from their colour.
There are several known early salt-workings in East Africa at Uvinza, east of Kigoma in Tanzania, at Kibiro on the shores of Lake Albert in Uganda, at Basanga in Zambia and probably also at Sanga in Zaïre and in the Gwembe valley in Zambia. The salt extraction at
Uvinza was probably rudimentary as the fifth- and sixth-century finds at the salt springs were not associated with the stone-lined brine tanks which characterized the second-millennium occupation. Salt springs were also the source of the salt at Kibiro where an elaborate boiling and filtration process may date from the first millennium of our era; as there would be very little raison d’être for occupation at the site otherwise. At Basanga the
salt flats were occupied from as early as the fifth century and suggest an early, though so far not definitely established, exploitation of the salt, probably by evaporation processes.
Salt elsewhere was probably made in the variety of ways which persisted until the nineteenth century which involved burning and boiling grasses, or even goat droppings, from areas of known high soil-salt content, and then evaporating off the brine so obtained
and filtering out all the large impurities. Colander vessels used in such processes are common throughout iron age contexts but unfortunately such perforated vessels could also be used for other food preparation processes, which makes the certain ascription of salt-making often very difficult.
Author: M.Posnansky. Historian and archaeologist; author of a number of important works on the archaeological history of East Africa.
Source: General History of Africa Vol.II. [Editor: G.Mokhtar] Ancient Civilisations of Africa. Chapter 29.The societies of Africa south of the Sahara in the early iron age.