This art celebrates the fusion of two strange branches of the history of medicine, and its 18th century links to entertainment. German physician and astronomer Franz Anton Mesmer, the father of "mesmerism", (the 18th forerunner of hypnotism), was influenced by the English physician Richard Mead, Mesmer incorporated Mead’s theories that the  gravitational pull of the planets affected human health by acting upon an invisible fluid found in the human body. In 1775 Mesmer revised this theory into his own as “animal magnetism”. These fluids he concluded could be manipulated by the use of magnetized objects, to clear the body of disease caused by their incorrect flow.  Practising his method to growing popularity in Vienna, he relocated to Paris in 1778, after being accused by Viennese physicians of fraud. Finding success in Paris, he was again accused in 1784 by Parisian doctors of fraud. In response King Louis XVI appointed a commission of scientists and physicians to investigate Mesmer’s claims and methods. The committee included the American ambassador Benjamin Franklin and the French chemist Antoine-Laurent Lavoisier. The committee finally concluded that there was no scientific basis for Mesmer’s claim, or the existence of the fluid in the body, and the movement named for him declined. 

Incidentally Richard Mead is also known for his medicinal cure all ‘Snail Water’, his recipe recorded in his work ‘A Short Discourse concerning Pestilential Contagion, and the Method to be used to prevent it’, published in 1720. Dr. Meads recipe, for use by the poor who could not afford more expensive treatments, called for the use of snails, worms, berries and a mixture of herbs, which would need to be ingested by the patient. 
My interpretation of snail water can be found in the 'apothecary bottles and jars' section of the website.