Phenolax wafers contained a gentle
laxative called phenolphthalein. They were introduced by The Upjohn
Company in 1908, inside an embossed glass bottle with no
label. Phenolax was an instant hit. 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! This page contains a January 1986 article about it and photos of
Phenolax wafers, bottles and a box.
Here's a page that shows Phenolax store displays from the
first half of the 20th Century.