One of the first
sedatives was developed in
Germany in the 1860s from
apples and
urine. In fact, from what I've read, the name
barbiturate comes from
Barbara - the
waitress who provided the urine for the first
experiments.
Unfortunately, there is no
documentation for how in 1865 Adolph Baeyer came up with the idea that combining the
urea from urine and
malic acid from apples would induce
drowsiness.
Speculate on that yourself. However, what followed was a significant amount of
laboratory research to find out exactly why it worked, and the first sleeping drug
barbital appeared in 1903.