soon
becomes stained with black products of the sulphur which has chemically
acted on the steel blade of the knife. Furthermore, the peel, or skin
of the potato, embodies a narcotic principle known as " solanin."
Ladies in former times had their dresses supplied with small bags, or
pockets, in which to carry one, or more such small potatoes next their
person against rheumatism. But this "solanin" is dissipated, and
rendered inert when the whole potato is boiled, or steamed.
IRON AND ZINC.
Among the
Metals put to more ordinary uses, Iron and Zinc are to be classified;
though not generally esteemed as " Noble," for personal adornment, or
as aiding jewelry. The former of these Metals serves admirably for
making handcuffs, and the latter for foot-pans ; neither of which
purposes comes within the range of our present treatise.
All
the native Iron met with is believed to have fallen from the sky. The
Iron of commerce is obtained from its ores; the Tin of commerce from
Casiterite, or tinÂstone, a compound of Tin with oxygen.
With
respect to Iron, we have shown when treating of the Bloodstone that to
wear a fragment of this stone externally on some part of the body will
indisputably serve to stay any flux of blood from which the wearer may
be suffering ; doing so by reason of the diminutive specks of red iron
oxide incorporated within its substance. This subtle effect is fully
justified by the similar action which small doses of metallic Iron
given internally are found to exercise. Such doses, nevertheless, are
not absorbed in any degree ; they pass out of the system absolutely
undiminished in weight, together with the
