If you have a specimen with fat adhering to the skin in more or less loose patches, as in hawks and owls, simply scrape or peel the fat off with a knife and thumb and finger.
If a fat duck skin is to be prepared the inside layer of skin over the fat tracts must be sheared off carefully with scissors and the fat then removed with a skin scraper or dull knife blade, care being exercised not to tear the outer skin or to pull through feathers with the grease.
To clean and degrease a bird skin which requires such treatment to prepare for mounting, wash it first in lukewarm ammonia water with mild soap. Squeeze from this washing and put through a bath of half-and-half alcohol and spirits of turpentine. Squeeze from this thoroughly and run through benzine. Compress and relax the skin repeatedly while immersed in both these baths. When squeezed from the benzine, dry the plumage by first burying the skin for some minutes in dry plaster of paris.
When nearly all the moisture is drawn out dust skin in the plaster until natural fluffiness is restored. Do this last out of doors, where the skin may be beaten well when thoroughly dry, to free it of plaster dust. Lay skin, right side out, over the left hand and beat with the right, giving an occasional shaking, the better to loosen plaster dust.
Fig. 2.
An A1 duster may be made from the brush of an ox tail. Nail this on a short piece of broomstick and square ends of hair with scissors. This duster is used instead of beating the plumage with the hand and does the work much quicker and better. When the dusting is done turn the skin inside out again (see [Fig. 2]) and brush arsenic-water into all inner surfaces, then turn skin right side out and brush a little of the solution upon the feet, under side of wings, and inside the bill.
When poisoning the head, with skin inside out, one step in preparation for mounting is to be taken. After the arsenic-water is applied to skull and scalp, fill eye sockets with chopped tow or fine excelsior, put a light layer of cotton smoothly around the skull, forward edge close down to bill. Turn skin carefully back over skull and finish poisoning skin.
It is best, if possible to do without risk of decay, to fold the freshly prepared skin in a clean paper, wrap in damp cloth, and lay over one night in a cool place, before mounting. This allows arsenic-water to penetrate through into base of plumage, thus becoming more effective against moths than if skin were immediately filled with absorbent material which would tend to draw out the freshly applied solution.