Nick Maclaren wrote:
Or Scheele's acid, for those that are truly stuck in a time warp.

Gosh, you must be old to remember that ! ;-))
I googled "Scheele's acid" and the first find gave me :-
"Taylor, Lond. Med. Gaz., 1845, p. 103,
a man took 45 drops of Scheele's acid;"