Upon the preceding principles and experiments depend the several
processes employed for protecting substances from putrescence and
corruption. Here we must distinguish between those bodies which may be
preserved by any media suitable to the purpose, as anatomical
preparations or objects of natural history, and those bodies which being
intended for food, can be cured only by wholesome and agreeable means.
A common method for preserving animal substances unchanged in property
and texture, is to immerse them in a spirituous liquor containing about
65 or 70 per cent. of real alcohol. Camphor may also be dissolved in it,
and as much common salt as its water will take up. A double fold of
ox-bladder should be bound over the mouth of the vessel, in order to
impede the evaporation of the watery portion of the liquid, and its
upper surface should be coated with a turpentine varnish. Undoubtedly a
little creosote would be of use to counteract the decomposing influence
of the alcohol upon the animal substances. With such an addition, a
weaker spirit, containing no more than 30 per cent. of alcohol, would
answer the purpose.
Instead of alcohol, a much cheaper vehicle is water saturated with
sulphurous acid; and if a few drops of creosote be added, the mixture
will become very efficacious. A solution of red sulphate of iron is
powerfully antiseptic; but after some time it gives a deposit of the
oxide, which disguises the preparation in a great degree.
According to Tauffier, animal substances may be preserved more
permanently by a solution of one part of chloride of tin in 20 parts of
water, sharpened with a little muriatic acid, than even by alcohol.
For preserving animal bodies in an embalmed form, mummy-like, a solution
of chloride of mercury and wood vinegar are most efficacious. As there
is danger in manipulating with that mercurial salt, and as in the
present state of our knowledge of creosote we have it in our power to
make a suitably strong solution of this substance in vinegar or spirit
of wine, I am led to suppose that it will become the basis of most
antiseptic preparations for the future. From the statements of Pliny, it
is plain that wood vinegar was the essential means employed by the
antient Egyptians in preparing their mummies, and that the odoriferous
resins were of inferior consequence.