He became depressed and despondent, feeling that his own accomplishments were forgotten. In 1931, he killed himself via mercury poisoning, and took four agonizing days to die as the mercury burned its way through his body.
He became overwhelmed by feelings of insignificance and despair, convinced that his achievements were being erased from memory. His struggles ultimately led him to take his own life through mercury poisoning in 1931, a painful and drawn-out process.