On giving flexibility to Botanical and Zoological specimens. 101 
I then remembered that General Totten, of the U. S. Engineers, 
had mentioned to me, some years ago, his success in preventing 
the cracking and peeling off of the epidermis of various shells, 
by impregnating them with chlorid of calcium. I also remem- 
bered Boucherie’s experiments with the same substance in giving 
flexibility to wood. The principle that a substance which is 
flexible when moist, will remain permanently moist, and therefore 
permanently flexible, when impregnated with a deliquescent salt, 
1s So obviously true that it needed no experiments to convince me 
of its applicability to the fragile plants above mentioned, and to 
many other specimens in natural history. But as practical diffi- 
‘culties often occur in the application of correct principles, I have 
tested the process by numerous experiments in which chlorid of 
calcium was employed to give flexibility to various vegetable 
and animal products, and the results have fully equalled my ex- 
department, find many useful applications for this process. 
The mode of application which I have employed Is to immerse 
the dry specimen for some time in a neutral saturated: solution of 
chlorid of calcium, (which any one can make for himself by sat- 
warm wat ion in the salt. A speedy impregna- 
ion will bunch piadipnioe which the specimens, if plants, 
