Salt industry modern

Colburn says: "It should not be overlooked that the manufacture and distribution of salt as an article of commerce is a thing of history, and has attained its enormous dimensions within the past century and a half. It is inconceivable that in past times the population of the world, made up as it was largely of pastoral and nomadic people inhabiting the interior of the great continents, should have supplied themselves with salt as an ingredient of food as we do. The omission of any mention of it in the older chronicles and even among the more perfect records of the classics, except at the luxurious tables of the rich, goes to confirm this supposition."