range of theories and practices collectively denoted mesmerism, research has clearly identified that there are substantial and significant differences between "mesmerism" and "hypnotism" however they may be defined. Vital fluid and animal magnetism A 1791 London publication explains Mesmer's theory of the vital fluid: Modern philosophy has admitted a plenum or universal principle of fluid matter, which occupies all space; and that as all bodies moving in the world, abound with pores, this fluid matter introduces itself through the interstices and returns backwards and forwards, flowing through one body by the currents which issue therefrom to another, as in a magnet, which produces that phenomenon which we call Animal Magnetism. This fluid consists of fire, air and spirit, and like all other fluids tends to an equilibrium, therefore it is easy to conceive how the efforts which the bodies make towards each other produce animal electricity, which in fact is no more than the effect produced between two bodies, one of which has more motion than the other; a phenomenon serving to prove that the body which has most motion communicates it to the other, until the medium of motion becomes an equilibrium between the two bodies, and then this equality of motion produces animal electricity. According to an anonymous writer of a series of letters published by editor John Pearson in 1790, animal magnetism can cause a wide range of effects ranging from vomiting to what is termed the "crisis". The purpose of the treatment (inducing the "crisis") was to shock the body into convulsion in order to remove obstructions in the humoral system that were causing sicknesses. Furthermore, this anonymous supporter of the animal magnetism theory purported that the "crisis" created two effects: first, a state in which the "[individual who is] completely reduced under Magnetic influence, although he should seem to be possessed of his senses, yet he ceases to be an accountable creature", and a second "remarkable" state, which would be "conferred upon the [magnetized] subject … [namely] that of perfect and unobstructed vision … in other words, all opacity is removed, and every object becomes luminous and transparent". A patient under crisis was believed to be able to see through the body and find the cause of illness, either in themselves or in other patients. The Marquis of Puységur's miraculous healing of a young man named Victor in 1784 was attributed to, and used as