The Western Hemlock features chapters on the effects of the plant and how some are able to build up a tolerance for its poisonous effects. Hemlock is one of two highly poisonous flowering plants. Native to Europe, the Mediterranean region and southern Africa, hemlock is commonly known as poison hemlock, devil's bread, beaver poison, herb bennet, musquash root, poison parsley and spotted hemlock. The plant contains many toxic chemicals, including coniine, a substance similar to nicotine. Due to this chemical's potency, ingestion of the flower can easily result in respiratory collapse and death. In Ancient Greece, Socrates famously drank hemlock after being condemned to death by an Athenian jury in 399 BC. While the plant is capable of killing those who ingest it, hemlock is used in small doses in sedatives. Greek and Persian physicians even used the plant to solve problems like arthritis.