Poisons Basic Overview - Writers and poisons

I recently saw a mug on Pinterest that said "this may contain Iocaine powder", but is Iocaine an actual poison? Inconceivable! It is completely fictional. Fellow writers, pick your poison. This is a basic overview of poisons, some of them we see every day and use in smaller-than-fatal doses. It's all about dosage, frankly, especially in drugs (which can always be a poison). Plenty of suicides have been done by overdosing on drugs. Most of the poisons we hear about in mystery novels are actually natural substances being misused in larger dosages and being used incorrectly. Was it deliberate? Depends on the poison itself. Also, some of these are and were used medicinally, again all about how much you breathe in, consume, and soak into your skin. I'm going to talk about the most common poisons in mystery genre novels. Those include ricin, arsenic, and Strychnine. The most fatal will be first and least fatal last, but all are fatal. Ricin Ricin comes from...