In the first half of the twentieth century, brands marketed soda and mineral waters for their digestive benefits. Families in working-class neighborhoods constantly worried about the health problems related to unsanitary conditions in food and water and products like “Pluto Water” offered one solution. There were many products marketed to this end, from Johannes Hoff’s malt extract to the “Milk of Magnesia” still in common use today. This image shows Johannes Hoff’s malt extract (left), Milk of Magnesia (center), and Pluto Water (right.)