Arsenic
Arsenic is one of the oldest medicines that dates back to ancient times. However, even though the toxic properties of arsenic were known, the chemical was used to treat various diseases up until the 20th century. Arsenic compounds were ingredients in many tinctures, balsams, and tablets, which were used to treat diseases such as trypanosomiasis, or “sleeping sickness,” and syphilis.
#18 The idea is that of sympathetic (imitative) magic : mices have good teeth, so they are good for ailing teeth... the same kind of "reasoning" is always used nowadays in... homeopathy !
#19 Some trepanated prehistoric patients have survived long enough for the bone to grow again around the opening !
#1 Maybe one was supposed to have masturbated with a handful of cornflakes. That certainly would have made it a lot less fun. (Cream on your cornflakes, anyone?)