374i GUANO. 



1003. The composition of the inorganic part of 

 such manure, like that of the organic, varies con- 

 siderably. The following shows the composition of 

 10,000 parts of the inorganic matter in yard dung 

 (Richardson) : — 



Potash .322 



Soda 273 



Lime 34 



Magnesia .26 



Sulphuric acid - . 327 



Chlorine .315 



Soluble silica 2705 



Phosphate of lime . . . ... . 71X 



Phosphate of magnesia 226 



Phosphate of iron 468 



Phosphate of manganese . . . . trace 

 Phosphate of alumina (?).... trace 



Carbonate of lime 934 



Carbonate of magnesia 163 



Sand 3099 



Alkali and loss 397 



10,000 



1004. The putrefied dung of birds has of late 

 years been much employed as manure, under the name 

 of guano. The composition of this substance varies 

 greatly, according to the extent to which decomposi- 

 tion has proceeded, and the degree to which it has 

 been exposed to the atmosphere. The following 

 table shows three different analyses of guano : — 



