A specimen with a damaged or imperfect skin may yield a good skeleton and in the case of something very rare both the skin and skeleton may be mounted separately. This process is one calling for a skilled operator as all claws, nails or hoofs should remain on the skin while their bony cores are part of the skeleton.
In the preservation of rough skeletons, skinning by any method is the first step, next the removal of the viscera, etc., then the most of the flesh and muscle should be dissected off the bones, after which poison with dry arsenic and put where it will dry out quickly and be out of the reach of foraging animals.
The legs of small animals should be unjointed as well as the skull and after trimming be put inside the body cavity and securely tied to prevent loss; birds are treated about the same and all large animals are pretty thoroughly taken apart in order to properly clean the bones.
Always remember that a skeleton with parts cut away or bones lost is about as good as none. Leave any cartilage attachments and any parts of a bony nature for the osteologist, to be on the safe side. Sometimes along salt water an uncleaned skeleton may be put in a wire netting cage and anchored in the water where various small marine animals will soon clear away the flesh. On land, too, a similar expedient may be practiced by putting small carcasses in a box with holes bored in it and burying it in some active ant hill. In both cases the openings need to be small, that the smaller bones may not be carried off and they should be removed before the ligaments are destroyed.
When they are not wanted for scientific purposes, skulls may be cleaned with the minimum labor by boiling. Watch them closely, however, and remove as soon as the flesh gets tender as much cooking will cause the teeth to fall out and the skull to separate at the sutures. Glue and plaster paris will put such disintegrated skulls in shape for commercial mounting but they are ruined forever for the scientist.
A friend was once cleaning a quantity of skulls (for museum purposes) and to expedite matters put them on to boil; all went well as long as the pot was watched, but an accident, the collapse of a large building, called him away and prevented his return until a dozen or so skulls had turned to a mass of loose teeth and scraps of bone. I never knew just what transpired between him and the museum curator afterward, nothing of interest to the general public.
Small specimens which it is proposed to skeletonize are best preserved entire in alcoholic solution as loss and breakage are thus prevented. The solution of formaldehyde can be used for this purpose but is not as good as it toughens the flesh, making its future removal more difficult. The complete cleaning of a skeleton is a matter of much soaking and scraping, calling for much patience and a strong stomach. Ligamentary skeletons of the smaller birds and animals are often prepared and mounted by the non-professional with fair success.
The entire specimen is cleaned of all flesh without disconnecting any of the bones except the skull and the leg of all but the smallest species.
The spinal cord is replaced with a brass or galvanized wire of suitable size and length; this should project enough to penetrate a piece of cork fitted to the cavity of the skull. If the leg bones were removed they should be fastened back in place by drilling small holes through them at the joints, inserting a piece of brass wire and clinching the ends over.