Animal magnetism promised a rational explanation for illness in a guise that strongly resembled the major physical discoveries of the period. The Romantic era was the era of occult forces, empirically verified.

The invisible had been captured, tamed, generated, and most importantly measured. Lightning turned out to be mere electricity, and could be piped through rods. The wandering gods were discovered to have been pulled by the same horse that holds you to the ground. Humans could sit on chairs in the sky by filling space with expansive vacuum, in the form of helium.

Electric current moved dead animals. What a shock. Imagine how the religious literalists must have felt and reacted. Yahveh’s breath of life was being threatened by twitching frogs’ legs. My soul ain’t no electricity! is as much a noble defense of Almighty God as I ain't kin tuh no monkey! and I didn't evolve outta no mud!

I mention this to evoke the shock of it all:

And also starring:

Things ghostly, poetic, religious, and magickal were condensing into material gels. With the discovery that so many occult powers were actually physical substances, it is no certainly great leap to claim that an invisible fluid connected the human body with all of nature.