198 THE LIFE OF A BIRD. 



the oddest sort of taste, used to employ it in pre- 

 ference to common chalk. The shell cleared from 

 its living membrane, used to be boiled and some- 

 times calcined, after which it was laboriously 

 reduced to the finest powder, and taken in suitable 

 doses. With the same view, and apparently pos- 

 sessed with the idea that the mere singularity of 

 a remedy would ensure its successful operation, 

 powdered crabs' eyes, and the shells of fish, were 

 used largely in medicines. As an item in the phar- 

 macopoeia it need scarcely be said that egg-shells 

 are now entirely wanting ; the white and the yolk, 

 however, remain, and prove valuable for certain 

 medicinal purposes. The composition of the egg- 

 shell has been thus represented by Vauquelin : 



Carbonate of lime 96* 



Animal matter 2 



Phosphate of Lime and Magnesia .... 1 



Carbonate of Magnesia \ 



It is very probable, however, that these propor- 

 tions vary with the health of the animal, and with 

 other circumstances of which we remain ignorant. 

 Still, the broad outline of the chemical composition 

 of the shell will remain much the same. It is not 



