When I became convinced that arsenic was injuring my health, and that of others, I began to experiment upon other substances, and after trying a quantity of various things, have succeeded in manufacturing a nearly odorless compound which has the following advantages over arsenic: It thoroughly preserves the skins of birds, mammals, reptiles, and fishes from decay, and also prevents the attacks of dermestes or anthrenus, while the feathers of birds and hair of mammals are not as liable to be attacked by moths as when the skin is preserved with arsenic. This preservative when properly applied abstracts the oil from greasy skins, thus preventing them from becoming decayed through carbonization, as nearly always occurs in ducks’ skins after a few years. It is a deodorizer, all disagreeable smells leaving the skin to which it is applied; and above all it is not a poison. I used this dermal preservative, as we have named it, as an absorbent while skinning birds, especially small ones, as then the plumage is dusted with it necessarily, which insures more or less protection to the feathers from the attacks of moths.
To render my preservative, or indeed any other, effective, it must be thoroughly applied to the skin; all the portions, especially those to which any flesh adheres, must be well covered with it, and the fibre of the muscles should be broken up as much as possible. But a small portion, at best, of arsenic is soluble in either water or alcohol, and but a little in the juices of the skin, whereas in my dermal preservative at least three-fourths of that which comes in contact with a moist skin is absorbed, thus thoroughly preserving the specimen. In the case of a greasy skin, remove as much fat as possible by peeling it off or gently scraping until all the little cells which contain the oil are broken up and the skin appears; then coat the skin liberally with the preservative, when it will be found to absorb the oil. Allow this layer to remain a few minutes, then scrape it all off and coat again with a fresh supply. Continue to do this until all the oil that will flow out is absorbed, and then dust with a final coating.
There are two chemical processes carried on in preserving oily skins, one of which converts the oil into soap, and this is in turn absorbed and dried. Thus the preservative which has been scraped from the skin can be after a time used again, as it has lost but a small portion of its efficiency. It might be borne in mind, however, that all the fat cells possible must be broken up, as the skin which surrounds these is, in a measure, impervious to the preservative, which must, in order to absorb oil, come in contact with it.
Section V.: Other Methods of Preserving Skins.—Skins may be temporarily preserved by simply using black pepper, but the effect is not lasting. The same is true of tannic acid, but either of these, alum, or even common salt, will do as a substitute for the preservative until the skins can be got into the hands of a taxidermist, or until the collector can procure the proper preservative. I will here mention that the dermal preservative costs only twenty-five cents per single pound, and this quantity will preserve at least three times as many skins as the same amount of arsenic.
A good method by which large skins may be temporarily preserved is by salting them. Simply coat the inside of the skin with fine salt, turn it, smooth the feathers and fold the wings neatly, then pack in paper. The salt prevents the skin from quite drying, and thus it can be moistened much more readily, and made into a skin or mounted. The advantage of packing large birds in so small a capacity is obvious to any one. Two collectors whom we have had out the past season have sent in some thousand large skins in this condition; and these we shall endeavor to work up within six months’ time, as salted skins become quite brittle if allowed to lie too long. They should be kept in a dry place, as salt absorbs moisture, which causes the skin to decay. They are also liable after the first year to be attacked by dermestes and anthrenus.
Birds which are in a bad condition through having been dead a long time may be sometimes skinned, in case of rare specimens, by using great care. Sprinkle the inside of the skin well with preservative, as this tends to set the feathers, being a stringent, keeping the skin as straight as possible, as folding it is liable to loosen the feathers. The intestines of birds may be removed and the cavity salted when large birds are to be sent from a distance.
CHAPTER III.—MAKING SKINS.
Section I.: Cleaning Feathers.—If a bird is bloody, the feathers may be washed either in turpentine or water. Saturate a rag or piece of cotton, and clean off the blood, which if dry may require some soaking. Try to keep the water from spreading as much as possible, but be sure that every particle of clotted blood is removed and the spot washed thoroughly. Then dry by covering the spot well with either plaster or dermal preservative, the latter being preferable as it never bleaches the plumage. This should be worked well into the feathers with a soft brush, aided by the fingers, applying a fresh supply constantly until all the moisture is absorbed; then dust with a soft duster. In case of grease-spots, if fresh, use the dermal preservative alone, but if old and yellow use benzine to start the grease, and then dry with preservative, when it will generally be found that all stains will be removed; but in some cases two or three applications of benzine may be necessary. Small spots of dried blood may often be removed from dark feathers by simply scraping with the thumb-nail, aided by a moderately stiff brush, much after the manner in which a living bird removes foreign substances from its plumage. Do not leave clotted spots of blood in the plumage, as the feathers never lie well over them, and such places are liable to be attacked by insects, and even a spot of blood under the wing should, in my opinion, always be removed. Before any attempt is made either to make a bird into a skin or mount it, it should be thoroughly cleansed. Stains of dirt may be removed with alcohol, which dries more readily than water, but it will not start blood as well as turpentine or water.