France in the late 19th and early 20th centuries saw increased use of salt in food advertising and preservation. Canned fish products like sardines were soaked in brine during processing. Meat extracts, popularized by Liebig, contained 4% salt initially but some brands increased this to 25%. The mining of potash, used as fertilizer, became an important industry, helping crops like wheat and vegetables. Many food advertisements from this era featured canned goods and promoted the use of salt and meat extracts in cooking and agriculture.