The logic by which the treatments current in folk-medicine acquire their efficacy is passing strange; at first acquaintance with this wonderland we are apt to imagine ourselves in some weird topsy-turvydom, where everything uncanny and incongruous is greedily collected, and the most bizarre and trivial doings become endowed with marvelous efficacy. Upon closer acquaintance we discover some little order in the medley, and, in spite of much that remains arbitrary and capricious, we begin to trace the analogies according to which the various treatments are composed and the potions concocted. The common connection of toads with warts, both as giving and curing them, is due to nothing more than the warty appearance of the toad's skin; similarly, in Gloucestershire, against ear-ache a snail is pricked and the froth that exudes dropped into the patient's ear (Black); and this by reason of the snail-like passages in the ear. Fevers being connected with heat and blood, and both these closely associated with red, red things become efficacious in diseases characterized by fever. That this should be especially in vogue against scarlet fever is no more than natural; and it is related that when the son of Edward II. was sick of the small-pox, the physician directed that the bed-furniture should be red (Black). Other forms of such associations will be met with in the discussion of the doctrines of signatures and sympathies.
Folk-medicine forms a particularly apt field for the application of the two general forms of analogy indicated as prevalent among savages: analogies by contrast and the assignment of unusual effects to uncommon causes. If something is done with the right hand, doing it with the left reverses the action; one set of directions applies to men and contrary ones to women; saying a thing backwards is particularly efficacious. The prescription against hiccough, that you should "cross the front of the left shoe with the forefinger of the right hand while you repeat the Lord's prayer backwards" (Black) may serve to illustrate the one crooked type of argument, while for the other we have only to recall the Shakespearean witches, with their--
"Round about the cauldron go; In the poison'd entrails throw. Toad, that under coldest stone, Days and nights has thirty-one Swelter'd venom sleeping got, Boil thou first i' the charmed pot! Fillet of a fenny snake, In the cauldron boil and bake; Eye of newt and toe of frog, Wool of bat and tongue of dog, Adder's fork, and blind-worm's sting, Lizard's leg, and owlet's wing, For a charm of powerful trouble, Like a hell-broth boil and bubble. Scale of dragon, tooth of wolf; Witches' mummy; maw and gulf, Of the ravin'd salt-sea shark; Root of hemlock digg'd i' the dark; Liver of blaspheming Jew; Gall of goat, and slips of yew, Silvered in the moon's eclipse; Nose of Turk, and Tartar's lips; Finger of birth-strangled babe, Ditch deliver'd by a drab,-- Make the gruel thick and slab; Add thereto a tiger's chaudron, For the ingredients of our cauldron. Cool it with the baboon's blood, Then the charm is firm and good."