Lacteoline - medical advertising poster featuring a mermaid. The "medicine" is Bath salts, a fragrant blend of mineral salts added to bath water. They are used to flavor and color the bath, or sometimes between advertisements that accompany them: soften skin or water, to circulate the blood in the body, providing micronutrients ... Some contained dyes that can adhere to the skin, making it more vulnerable to irritation and disease. Known as the father of the modern poster, Jules Chéret (1836 – 1932) was a French painter and lithographer. He worked on everything from theater to advertising.