96 ANIMAL EESOUECES OF THE UNITED STATES. 



30. CHEMICAL PEODUCTS, &c— Continued. 



7c. Derived from protozoans : 



Burnt sponge, formerly used in medicine. 



Infusorial earth, and its applications. (See above, under K. 



31. FERTILIZERS. 



a. Natural guanos : 



Bat guano from caves. ' 



Bird guano from oceanic islands. 

 d. Artificial guanos : 



Menhaden guano. 



Herring guano. 



White-fish guano. 



Other fish guano. 

 c. Artificial fertilizers : 



Bone-dust ground for use. 



Bone phosphates. 



Dried meat from refuse of slaughter-houses. 



Poudrettes. 



Other animal fertilizers. 



32. LIMES. (See under 30.) 



33. OTHER MATERIALS NOT MENTIONED. 



