What poison killed Robert Johnson?

Robert Johnson, the legendary blues musician, is often rumored to have been poisoned, but the exact cause of his death remains uncertain. He died in 1938 under mysterious circumstances at the age of 27, with some speculating he was poisoned by a jealous husband or lover. However, the official cause of death was listed as "acute nephritis," likely related to syphilis or heavy drinking. The true details surrounding his demise continue to be a subject of intrigue and speculation.