134 PHILOSOPHY OF ZOOLOGY. 



progress of putrefaction until the specimen is dried. To re- 

 medy this evil, the corrosive sublimate is kept dry, and 

 mixed with equal quantities of burnt alum and tanners 1 

 bark, or coarse snuff, reduced to a fine powder. The ap- 

 plication of this powder facilitates the drying of the speci- 

 men, and at the same time powerfully retards the tendency 

 to putrefaction. When the drying is completed, it will be 

 safe from insect foes. Quantities of musk and camphor 

 are sometimes added, which conceal any disagreeable smell ; 

 but they m#y safely be omitted, as they are not necessary 

 to the future preservation of the object, while they add 

 to the expence attending its preparation. 



Arsenic has, in a great measure, usurped the place of 

 the corrosive sublimate, in the preserving powders which 

 are employed at present, as it does not injure the wires 

 which are occasionally employed in preserving the forms of 

 the specimens. But neither of these powders can be used in 

 the preservation of animals, without incurring the risk 

 of some of the parts drying too quickly, and proving 

 inconvenient to the operator. These evils, however, are 

 removed by the use of the arsenicaied soap, which is usually 

 made as follows ; White oxide of arsenic and soap, two 

 pounds each; sub-carbonat of potash, twelve ounces; quick- 

 lime, four ounces; and camphor five ounces; the whole beat 

 up into a uniform mass. This mixture lathers with water 

 like common soap, and may be applied by means of a 

 brush. It does not contract and dry up the parts like the 

 powders, but keeps them in a soft pliable state, counteracts 

 the tendency to putrefaction, and effectually protects them 

 against the attack of insects. It appears to have been first 

 used in the Public Collections at Paris. 



Many entire animals, and the parts of others, are of too 

 soft a consistence to suffer being dried, without the loss of 

 form and even texture. These are preserved in wide- 

 mouthed phials filled with alcohol. When the objects are 



