Feeling of suffocation. Face muscles contract and victim looks as if they're grinning. This is followed by very violent and distorting contractions, followed by a period of rest, then an attack of even more violent contractions. Patient is conscious but in agony, unable to speak because of lockjaw. Pulse is incredibly high.
Death is during a convulsion, from paralysis of respiratory system.
Cantharidin Spanish fly. When crushed and rubbed on skin, causes blisters. Taken orally, a small dose results in kidney damage. Larger doses inflame mouth, throat and stomach. Vomit and urine contain blood.