Sodium morphate
a favorite Mafia poison for centuries. Smells like apple pie, and is sometimes served up
in one, as to J. Edgar Hoover, sometimes in a pill or capsule. Symptoms include lethargy, sleep, sometimes vomiting. Once ingested, there is a
heart attack
and no trace is left in the body. Proof is in the vomit which is usually not analyzed. Not mentioned in your standard medical book on poisons, etc. It is a common ingredient in
rat poison.