Sir William Ramsay (b. October 2nd 1852) had a hand in the discovery of neon, argon, krypton and xenon, which suggests
the treatment of 11 across, 15, 17 and 18. They respectively have NE, KRYPT, ARG and XEN added ON the answer.
Ramsay was certainly not an alchemist. The shaded letters can be arranged to make NOBEL LAUREATE.
