Paracelsus, a 16th-century alchemist, and physician coined a great phrase: “All things are poison and nothing is without poison; only the dose makes a thing not a poison.”
Poisons
Arsenic Poisoning - A History | Curious Minds - Curious Minds Podcast
Arsenic 砒霜, compete with phosphorus in the chemical reaction that produces ATP
used excessively to kill people before the 19th century, until the Marsh Test which can identify minute traces of it in corpses was invented in 1830's.
Cyanide 山埃
Drugs
LSD History | Curious Minds - Curious Minds Podcast
LSD History, Pt.2: Timothy Leary | Curious Minds - Curious Minds Podcast
LSD is not addictive, and is one of the strongest drugs known to man
the common dose is a mere 50ug
comparing to that of cocaine 100mg