12 
specimen. A little alum is also of great use for rubbing into soft spots and 
wrinkles of the skin while dry-curing large pelts in damp weather. Alum 
is much better than salt for touching-up uncured spots in fresh skins, as salt 
absorbs moisture from the air, causing the soft areas to spread. If salt 
is used on a skin, it must be thoroughly spread on the whole flesh surface 
of the skin. 
The writer used arsenic-and-alum successfully for many years, but 
finally came to prefer arsenical soap ( See formula below) when making up 
study skins. Seton (1921, 274) states that he came back to arsenical soap 
after trying other preservatives, because it is “safe," and best of all because 
the soap in it dissolves and absorbs some of the grease in the skin. It is by 
no means a substitute for the removal of fat by scraping and other 
mechanical means, but there is usually a small amount of grease in the skin 
that can not be raised by scraping, and when this grease is dissolved by 
soap solution, it may be absorbed by sawdust inside the skin. 
The arsenical soap may be made as hard as desired and does not 
spill or leak. It may be kept in a wide-mouthed jar or tin, and when 
being used a sufficient amount on the top is softened with water and 
worked into a lather, which is applied to the skin with a brush. The 
liquid preservative touches and penetrates every part of the skin, soften- 
ing the areas that may have dried out during the skinning and cleaning 
operations. Fine hardwood sawdust is immediately sifted over the whole 
of the moistened surface, and the surplus shaken off. The sawdust is not 
essential to the curing process, but the thin layer of sawdust keeps the 
poison from coming into contact with the fingers, and the feathers and hair 
of the specimen, and also aids in drying the skin. The job completed, 
any wet residue of the soap is poured off the receptacle and the container 
may be put away without danger of spilling. The remainder soon dries in 
the air without waste. Arsenical soap will hardly be mistaken at sight for 
anything edible, and the admixture of camphor (a slight insect repellent) 
is a warning to the sense of smell. Arsenical soap may be purchased from 
dealers in taxidermists’ supplies, but it is easily and very cheaply made by 
Hornaday’s formula (1892, 346): 
White bar soap, soft rather than hard 2 pounds 
Powdered white arsenic 2 “ 
Subcarbonate of potash (bicarbonate of potassium) 6 ounces 
Camphor 5 “ 
Alcohol 8 “ 
“ The soap should be of best quality of laundry soap and of such composition 
that it can be reduced with water to any degree of thinness. Soap which becomes like 
jelly when melted will not answ'er and should never be used. Slice the soap and 
melt it in a small quantity of water over a slow fire, stirring sufficiently to prevent 
its burning. When melted, add the potash, and stir in the powdered arsenic. Next 
add the camphor, which should be dissolved in the alcohol at the beginning of the 
operation. Stir the mass thoroughly, boil it down to the consistence of thick molasses, 
and pour it into an earthen or wooden jar to cool or harden. 1 Stir it occasionally 
while cooling, to prevent the arsenic from settling at the bottom. When cold it 
should be like lard or butter. For use mix a small quantity with water until it 
resembles buttermilk and apply with a common paint brush.” 
Arsenic, borax, alum, and any of the dry preservatives may be kept in 
wide-mouthed bottles or wide-mouthed tins with friction-top or screw-top 
*An ordinary glass fruit jar or wide-mouthed bottle may be used if the mixture is sufficiently cooled 
not to crack the bottle. 
