Coniine is a volatile fluid alkaloid of hemlock (conium).

It is somewhat irritant to the skin and mucous mem branes, and is absorbed from the latter. It acts upon the terminations of the motor nerves causing muscular paralysis, while the brain may remain clear until respiration fails. It causes nausea and vomiting, and has but little effect on the circulation. Death is due to paralysis of the respiratory muscles.

It is rapidly excreted in the urine.