16 NATURALISTS’ ASSISTANT. 
This process which has been thus briefly described, is the 
property of Dr. H. E. Davidson of Boston, and to him all 
inquiries, as to the rights to use it, should be addressed. 
SKELETONS. 
Of fully as much importance as skins, and scarcely more 
difficult to prepare, are skeletons of vertebrates, and when 
from any circumstance it is impossible to prepare the whole 
skeleton, the skull can frequently be preserved. The modus 
operandi is essentially the same for all vertebrates. 
Skeletons are of two sorts, natural and artificial : z. ¢., those: 
where the bones are united by the ligaments, and those in 
which the ligaments are removed as well as the flesh, and the 
bones are articulated with wires and rods. Natural skeletons 
can only be prepared when the subject is of small size ; not 
exceeding the fox or goose in bulk. Skeletons of larger ani- 
mals must be, to a greater or less extent, artificially articulated. © 
The skin is first removed from all parts of the body, the 
head separated and the viscera extracted. ‘Then as much of 
the flesh as possible is removed with the scalpel, great care 
being taken not to cut, scratch or otherwise injure the bones. 
The body is then placed in cold water to macerate, some- 
times a little caustic potash is added to the water to ac- 
celerate the decomposition of the flesh, but except a gain 
in time there are no advantages to be gained by the ad- 
dition. For the first few days the water should be changed 
every day, and when the flesh is partially decomposed as 
much as possible is to be removed, taking care, if the skele- 
