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mice. Straw or hay is the best packing material, but moss, excelsior, etc., 
will do, the main point being to prevent the loose bones from rattling about 
and breaking. Seaweed should never be used for packing, as the salt 
gathers dampness. A little salt may be sprinkled on bones of a large 
animal if putrescent. Some aquatic mammals, such as seals and porpoises, 
can be packed in salt without detriment to their bones, but small skeletons 
should never be salted. Alum should never be used on a skeleton. 
Cleaning Skulls and Other Bones 
As cleaning and finishing skulls and skeletons is a more or less tech- 
nical laboratory process, most museums prefer to receive skulls and bones 
with merely enough superficial cleaning to prevent them from becoming 
offensive. Fresh muscular attachments, periosteum, and ligaments are 
tough, stringy, and hard to scrape off. After these attachments have dried 
hard they protect the specimen from breakage in shipment, and when 
softened in water they arc easily removed and with less risk of injuring 
the bony tissue. 
The method of cleaning skulls for scientific purposes is, however, rela- 
tively simple, and many private collectors will want to clean the mammal 
skulls in their collections. In some cases it is virtually impossible to 
determine species without examining skull and tooth characters, and this 
is hard to do unless the skull is cleaned. 
The simplest method of cleaning adult skulls and bones is by macera- 
tion, merely placing them in fresh water, in wooden barrels or stone crocks, 
and allowing them to remain a few weeks or months until the animal 
matter decays and disappears. This method is slow and causes an offensive 
smell, but where conditions permit its use, maceration probably gives the 
most satisfactory results. When carried on away from dwellings accidents 
may result in loss of the specimens, and when on city roofs the water 
becomes dirty with soot and discolours the bones. 
If only a few skulls are to be cleaned, they may be placed in fresh 
water and gently boiled until the flesh and ligaments are loose enough to 
be separated from the bone with a small scalpel or to be picked off with 
fine-pointed forceps. Be very careful not to scrape too hard and thus 
scratch the bone, nor to break off thin processes of bone, particularly around 
the eye or on the base of the skull. 
The collector has been warned to remove the brains from the skull in 
the field, as, if the brains are not removed before cooking, they may expand 
and force the brain case apart. If the brains are still in place, the skull 
should be first soaked in warm water and the brains removed with a bent 
wire, a pinhead, or a small scraper. A small (half-ounce) rubber syringe 
is very useful: one hand can operate the syringe while the other holds 
the skull under water. If the brain is thoroughly softened and broken up, 
the greater part of it can be sucked out with the syringe, instead of being 
forced out, with no danger of disarticulating the posterior part of the skull. 
If it is desired to whiten the skulls, rinse them off after cleaning and 
let them simmer for a short time with a little hydrogen peroxide in the 
water. If they are greasy, soak them for a few' hours in benzine or carbon 
tetrachloride. It is not generally advisable to whiten skulls very much, as 
it is hard to see the sutures in a chalky white skull when studying it. 
