Ricin is a highly toxic poison - with no known antidote - that is found naturally in castor beans.

REUTERS - Ricin, one of the deadliest poisons known, was found in a letter addressed to U.S. President Barack Obama, according to preliminary tests. Following are some key facts about ricin: - Ricin ...

Forbes contributors publish independent expert analyses and insights. I write about biodiversity and the hidden quirks of the natural world. Some poisons are known for creeping slowly through the ...