right him, and to snatch away his food or defile it by their
presence. They were afterwards driven away by his brothers-in-law,
ZETES and CALAIS. It has been suggested that originally the harpies were
nothing more than personifications of the swift storm-winds; and few
of the old naturalists, credulous as they were, regarded them as real
creatures, though this cannot be said of all. Some other fabulous
bird-forms are to be met with in Greek and Arabian mythologies, _etc_.,
but they are not of any particular interest. And it is time for us to
conclude our present excursion, and to seek for other byways.

V. THE POWDER OF SYMPATHY: A CURIOUS MEDICAL SUPERSTITION

OUT of the superstitions of the past the science of the present has
gradually evolved. In the Middle Ages, what by courtesy we may term
medical science was, as we have seen, little better than a heterogeneous
collection of superstitions, and although various reforms were
instituted with the passing of time, superstition still continued for
long to play a prominent part in medical practice.

One of the most curious of these old medical (or perhaps I should say
surgical) superstitions was that relating to the Powder of Sympathy, a
remedy (?) chiefly remembered in connection with the name of Sir KENELM
DIGBY (1603-1665), though he was probably not the first to employ it.
The Powder itself, which was used as a cure for wounds, was, in fact,
nothing else than common vitriol,(1) though an improved and more elegant
form (if one may so describe it) was composed of vitriol desiccated by
the sun's rays, mixed with _gum tragacanth_. It was in the application
of the Powder that the remedy was peculiar. It was not, as one might
expect, applied to the wound itself, but any article that might have
blood from the wound upon it was either sprinkled with the Powder or
else placed in a basin of water in which the Powder had been dissolved,
and maintained at a temperate heat. Meanwhile, the wound was kept clean
and cool.

(1) Green vitriol, ferrous sulphate heptahydrate, a compound of iron,
sulphur, and oxygen, crystallised with seven molecules of water,
represented by the formula FeSO4<.>7H2O. On exposure to the air it loses
water, and is gradually converted into basic ferric sulphate. For long,
green vitriol was confused with blue vitriol, which generally occurs
as an impurity in crude green vitriol. Blue vitriol is copper sulphate
pentahydrate, CuSO4<.>5H2O.

Sir K