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In preserving leather, care should be taken to avoid the use of oils or 
greases which acidify, as they will “burn” the leather and ruin it. Mineral 
oils are safe, but most animal and vegetable oils are to be regarded with 
suspicion unless their merits have been proved by long experience. Lano- 
line appears to be a safe emollient. 
Leather is, of course, very susceptible to the attacks of both moths 
and carpet beetles. Storing with naphthalene flakes and constant inspec- 
tion are necessary. 
Rawhide 
Rawhide demands much the same treatment as leather. In applying 
vaseline to soften the rawhide it is frequently necessary to avoid injury to 
paintings, as in the case of parfleches from the prairies. The vaseline 
should be applied warm, in very small quantities and on several occasions, 
always working on the unpainted side of the specimen. 
Drumheads, which are usually of rawhide, often cause much trouble 
by splitting. An application of vaseline soon after receipt of the specimen 
will do much to prevent this, but care should always be taken to keep the 
drums away from excessive heat. The splitting is often seen to start from 
the sharp edge of the drum hoop, rather than from weak areas in the drum 
head itself. It is sometimes advisable to round off the edge of the hoop, 
if the drum head can be removed without difficulty, and then replace the 
head. In most cases, however, the drum head is either nailed or laced into 
place and its removal uninjured is almost impossible. At times matters 
may be improved by slacking off the cross lacings at the back of the drum. 
The waterproof gut coats of the Eskimo are very apt to become 
extremely dry and brittle, so much so that they can hardly be handled 
without splitting them. Here, too, a thin coat of vaseline applied in very 
small quantities and thoroughly rubbed in will prove of value. 
Rawhide, in all its forms, is very likely to be attacked by insects, and 
should be inspected carefully and frequently. 
Shell 
Shell specimens are generally improved by immersion in a thin cellu- 
loid solution. If they are suspected of containing infiltrated salts, and 
their condition permits the treatment, soak them in several changes of 
pure water, until the silver nitrate test shows that all salt has been removed, 
then dry them and soak them in celluloid. 
Abalone shell specimens, including shell inlays from the west coast, 
whether abalone or opercula, are often marred by dirt and resin, which 
may be removed by means of wood alcohol or benzine. They should not 
be scraped or rubbed hard, as this would be likely to obliterate the minute 
surface corrugations that give rise to their iridescence. When inlays are 
found to be loose, they should be removed, the cavity thoroughly cleaned, 
and the inlay recemented in place with celluloid cement. In some cases 
the inlay, when replaced, will be found to be lower than the level of the 
surrounding material. Scraps of paper, cut to the correct size, should be 
soaked in celluloid and used to build the under surface of the inlay up to 
the correct thickness. 
