96 ANIMAL RESOURCES OF THE UNITED STATES. 
30. CHEMICAL PRODUCTS, &c¢ —Continued. 
k, Derived from protozoans: 
Burnt sponge, formerly used in medicine. 
Infusorial earth, and itsapplications. (See above, under K.) 
dL. FERTILIZERS. 
a. Natural guanos: 
Bat guano from caves. 
Bird guano from oceanic islands. 
b. Artificial guanos: 
Menhaden guano. 
Herring guano. 
White-fish guano. 
Other fish guano. 
‘ ¢ 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. 
