tained by distilling the exudation of different species
of fir; oil of turpentine passes over, and the resin remains behind.

_Why are the varieties of the cashew tribe, called varnish-trees?_

Because their large flowers abound in a resinous, sometimes acrid, and
highly poisonous juice, which afterwards turns black, and is used for
varnishing in India. One kind is the common cashew nut. All these
varnishes are extremely dangerous to some constitutions; the skin, if
rubbed with them, inflames, and becomes covered with pimples that are
difficult to heal; the fumes have also been known to produce painful
swelling and inflammation.

_Why do these varnishes, at first white, afterwards turn black?_

Because the recent juice is an organized substance, consisting of an
immense congeries of small parts, which disperse the sun's rays in all
directions, like a thin film of unmelted tallow; while the varnish which
has been exposed to the air loses its organized structure, becomes
homogeneous, and then transmits the sun's rays, of a rich, deep, uniform,
red colour.

The leaves of some species of Schinus are so filled with a resinous fluid,
that the least degree of unusual repletion of the tissue causes it to be
discharged; thus, some of them fill the air with fragrance after rain; and
other kinds expel their resin with such violence when immersed in water,
as to have the appearance of spontaneous motion, in consequence of the
recoil. Another kind is said to cause swellings in those who sleep under
its shade.--_Brewster's Journal._

_Why is the soap-tree so called?_

Because its bark, if pulverized, and shaken in water, soon yields a
solution, frothing, as if it contained soap. It is a native of Chili; the
trunk is straight, and of considerable height; the wood is hard, red, and
never splits; and the bark is rugged, fibrous, of ash-grey colour
externally, and white within.

_Why is a species of myrtle called the wax-tree?_

Because the leaves and stem, when bruised, and boiled in water, yield wax,
which concretes on cooling. Mr. Brande observes, "the glossy varnish upon
the upper surface of many trees is of a similar nature; and though there
are shades of difference, these varieties of wax possess the essential
properties of that formed by the bee: indeed, it was formerly supposed
that bees merely collected the wax already formed by the vegetable: but
Huber's experiments show, that the insect has the power of transmuting
s