Phenolax is one of my favorite Upjohn products. These wafers contained a gentle laxative named phenolphthalein. They were introduced by The Upjohn Company in 1908, inside an embossed glass bottle with no label. Phenolax was an instant hit as they worked well. Twenty million of these wafers were sold in the first year. The product was sold by Upjohn until 1988, which is a staggering 80 years! Here's a page on Phenolax.