Arsphenamine, Compound 606
Puzzle 17 of Famous Philosophers Hard Pack
Question is: Arsphenamine, Compound 606
and the answer is: SALVARSAN
Word Meaning:
SALVARSAN — (medicine) The organoarsenic compound arsphenamine, formerly used in the treatment of syphilis and the first effective antibiotic developed against any bacterial illness.
Definitions from Wiktionary.