Common resin.
Yellow beeswax (or paraffin wax).
Red ochre (in powder).
Oil of turpentine (turps).
The proportions of this luting are determined by putting more or less resin and red ochre, or turpentine and wax, as the "lithocolle" is to be more or less brittle or elastic. Melt the wax in the resin, then add the ochre in small quantities, and at each addition of this stir the whole briskly round. When the mixture has boiled seven or eight minutes, pour in the turpentine, stir it round, and set it near the fire to keep it warm some little time. To ascertain the quality, and if it requires more or less wax, put a little out on a cold plate, and note its degree of tenacity.
It is rather dangerous to prepare, and is best managed over a gas jet or stove, so arranged that the flame does not rise above the edge of the iron pot containing the composition; if this is attended to, not much danger can arise, especially if, in case of the composition firing, the lid of the pot be immediately clapped on.
Apply with an old brush, or by repeatedly plunging the neck of the bottle in the luting before the latter becomes cold. I have used an application of glue with great success on corks over spirits, by procuring the best glue, making it rather thin, and applying it whilst hot in successive coats. It will not do, however, for non-alcoholic solutions, nor for glass stoppers, from which it scales off when cold.
GENERAL REMARKS.
In all cases when "pickling" animals it must be remembered that the first pickle, whether alcoholic or not, is essentially deteriorated by the bloody mucus and water which exudes from the specimens, especially if large and "flabby;" this, of course, reduces the strength of the preservative medium. It is well, therefore, to have from three to four different vessels, in which the objects shall be successively immersed for several days, or even weeks, until, coming to the final preparation jar, they shall not stain the liquid in which they are ultimately to rest.
By using the various strengths of 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.