The author presents a compact survey of common salt covering its chemistry and physical properties, the historical origins of salt production, and a concentrated study of the Cheshire salt district. He traces ancient methods of boiling brine and the later adoption of rock-salt mining, and explains how mine collapse and freshwater inflow converted worked-out galleries into brine reservoirs. Detailed chapters describe evolving brine extraction and evaporation technologies, modern salt-making plants, and illustrated examples of apparatus. He also documents the social and commercial dimensions of the trade, including monopolistic practices, price struggles, and the economics of storage and market distribution, together with the local environmental consequences such as subsidence.