each preservative fluid one under
the other, in which to steep the specimens, proper results will be
obtained, by the exercise of a little forethought and judgment.
Filtration through blotting paper or charcoal is necessary from time
to time, and expensive spirits may be re-distilled when becoming too
weak by constant use.

Large fishes must have small cuts made in the walls of the abdomen to
allow the fluid to properly penetrate. In cases where the specimen is
not required for dissection, the removal of the viscera facilitates
the ultimate preservation.

If at 'any time it is necessary to throw away a quantity of
inexpensive spent liquor which may smell offensively, a small quantity
of the crystals of permanganate of potassa will instantly deodorise a
large quantity of fluid, and this without adding to it any offensive
scent of its own, as in the case of chloride of lime or carbolic acid.
The vessel must be afterwards well rinsed out in clean water, as 'the
potassa temporarily stains everything in contact a rich purplish red.

Some experiments which I conducted with benzoline incontestably proved
to me its valuable properties. I experimented on a Cornish chough--an
old specimen, infested with maggots or larvae of the "clothes" moth. I
immediately plunged it in benzoline, took it out, drained the
superfluous spirit off, and rapidly dried it by suspending it in a
strong current of air.

It took but a short time to dry, and, though the feathers were very
slightly clotted after the operation, yet, by a little manipulation,
explained hereafter, they soon arrived at their pristine freshness,
and all the insects which previously infested it were effectually
killed. I afterwards found on another specimen--a short-eared owl--two
or three larvae feeding on the feathers. I poured a little benzoline
over them in situ, and they fell off, apparently dead. I kept them for
a day, and by that time they were shrivelled and undeniably dead.

Here, then, we have the two elements of success--a perfect destroyer
of insects, and an agent not damaging, but positively beneficial, to
the feathers of birds when applied; added to which, is the remarkable
cheapness of benzoline. Caution--do not use it near a candle, lamp,
nor fire, as it gives off a highly inflammable vapour at a low
temperature; it also fills a house with a peculiarly disagreeable
odour, finding its way upstairs, as all volatile gases do; so it had
better always be used in