Botulinum toxin
In 1895 (seventy-five years later), Émile van Ermengem, professor of bacteriology and a student of Robert Koch, correctly described "Clostridium botulinum" as the bacterial source of the toxin. Thirty-four attendees at a funeral were poisoned by eating partially salted ham, an extract of which was found to cause botulism-like paralysis in laboratory animals. Van Ermengem isolated and grew the bacterium, and described its toxin, which was later purified by P Tessmer Snipe and Hermann Sommer.
Robert R. Williams
Robert Runnels Williams (February 16, 1886 – October 2, 1965) was an American chemist, known for being the first to chemically fully characterize and then synthesize thiamine (vitamin B). He first isolated thiamine in 1933, and synthesized vitamin B in 1935, reporting this in 1936. Williams also provided the modern name "thiamine" from the molecule's sulfur atom, and it being a vitamin (a class ultimately named for the earlier-known amine of thiamine itself).