Wiktionary
acetarsol
n. (context organic compound medicine English) The compound ''(3-acetamido-4-hydroxyphenyl)arsonic acid'' sometimes used as an antiinfective against the parasite protozoan ''Entamoeba histolytica''
Wikipedia
Acetarsol
Acetarsol is an anti-infective.
It was first discovered in 1921 at Pasteur Institute by Ernest Fourneau, and sold under the brand name Stovarsol (fourneau is the French word for stove).
It has been given in suppositories.