Placebo
Émile Coué, a French apothecary, working  between 1882 and 1910, discovered what later came to be known as the "Placebo effect". He reassured his clients by praising each remedy's efficiency and leaving a small positive notice with each medication. In 1901 Coué began to study under hypnosis. In 1913, Coué and his wife founded La Société Lorraine de Psychologie appliquée. His book Self-mastery through conscious autosuggestion was published in England (1920) and in the United States (1922).