Animal Magnetism
In a collection as rich in scientific content as the Vail Collection, it can seem odd to encounter subjects such as animal magnetism, spiritualism, and occultism. But during George Dering’s lifetime these subjects were being pursued in a spirit of serious scientific inquiry. This portion of the Vail Collection provides another valuable insight into the history of science, even as it gives us a sense of the breadth of Dering’s own interests.
The figure at the center of all this is Franz Anton Mesmer (1734-1815). In the latter half of the 18th century, Mesmer held a prestigious medical degree, but he devised a theory that illness resulted from an imbalance in a vital magnetic “fluid,” and asserted that he could cure virtually any illness by restoring harmonic balance. Animal magnetism was based on the assumption that this essential fluid could be manipulated, and that wellness could be restored when its flow through the body was corrected. Initially, Mesmer had subjects swallow iron filings, and then he passed magnets over their bodies. Later, however, Mesmer stopped using tools and would instead simply move his hands over his clients.

La vision, contenant l'explication de l'écrit intitulé, Traces du magnétisme, et la théorie des vrais sages, 1784
Mesmer had many fans and followers, including persons of note. But not everyone was impressed. In 1784, amid the cacophony arising from the widespread adulation and condemnation of Mesmer and his followers, King Louis XVI appointed two royal commissions to investigate the legitimacy of Mesmer’s claims. Mesmer was the talk of Paris in 1784, as evidenced by the large quantity of material published that year: the Vail Collection has roughly seventy-five items printed in 1784.
Both royal commissions condemned animal magnetism as false. The more prestigious commission included such important names as Antoine Lavoisier, Benjamin Franklin, Jean Sylvain Bailly, and Joseph-Ignace Guillotin.
Although Mesmer was discredited in France, animal magnetism continued to spark interest across Europe. Animal magnetism was particularly popular in England in the mid-1850s, and was commonly associated with the popular “science” of phrenology, as well as with spiritualism, seances, and the table-turning craze that had recently come to Great Britain from America. The Vail Collection contains many of the important works from this period, including a copy of William Davey’s The Illustrated Practical Mesmerist, which includes a slip advertising J.W. Jackson’s Lectures on Phrenology.
Animal magnetism had long-lasting effects on modern science and medicine. Most notably, James Braid (1795-1860) transformed the notion of animal magnetism into what would become modern hypnotherapy, which of course is currently used to treat such disorders as addiction and anxiety. The Vail Collection includes a copy of Braid’s 1852 edition of Magic, Witchcraft, Animal Magnetism, Hypnotism and Electro-Biology.
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