in the Indian's turban, the partiality for red head-kerchiefs evinced
by the native women of South West Africa ; and the red oil used by the
Papuan tribes for lubricating their limbs, and anointing their bodies.
has been found by a series of experiments carried on at the Finsen
Institute, Copenhagen, that light affects the blood materially.
Darkness will reduce its total amount by three per cent; decreasing at
the same time the quantity of blood in the heart. And red light has a
precisely similar effect. But blue light augments the amount of blood,
whilst increasing the quantity contained by the heart. Animals born in
the dark, or in red light, have a greater weight than those born under
ordinary conditions but only half the amount of blood.
to the genuine character of precious Stones, Mr. Harry Emanuel tells
that " the tourmaline is sometimes mistaken for the ruby ; the pink
topaz for the balas ruby; and occasionally the white sapphire, as
likewise the white topaz, pass for the Diamond,—even with those persons
who profess to be acquainted with Gems. But the tables of " hardness,"
" specific gravity" ; and " electrical properties," should prevent any
one from falling into such errors, since nothing can be more easy than
from these given data to ascertain to which class any particular Stone
belongs." A special endowment of the Diamond, by which its
genuineness, or its spurious character, may be determined, is its
single refraction of transmitted light. This particular property among
precious stones appertains only to the Diamond, the Garnet, and the
Spinel Ruby. Furthermore, a ready method, which is fairly reliable, for
telling whether or not Stones are genuine, is to touch them with the
tip of the tongue; when the true stone will give a colder