284 SUPERFICIAL DEPOSITS 



For the sake of comparison some analyses of other similar guanos are added. 



Average Composition of Seventy-eight Peruvian Gttanos. 



Per Cent. 

 Moisture ............ 13-67 



* Organic matter and ammonium salt ...... 5205 



Alkaline salts containing 3'34 per cent. P205 = 6-89 phosphate\ „ „_ 

 of lime .......... J 



Sand and insoluble . . . . . . - . 1"83 



100 



* Containing ammonia, 16-52. 



Angamos. Ballestas. Ichaboe. Patagonian. 



Nitrogen 20 11 9 4 



Phosphate of lime ... 10 23 26 40 



COMMERCIAL VALUE OF THE ADELIE PENGUIN GUANO 



The composition of a guano depends very considerably upon its age and the 

 amount of weathering and leaching to which it has been subjected. As a general 

 rule, unless the guano has been deposited in caves or sheltered places, the result is 

 a gradual diminution of the nitrogen and a corresponding increase in the phosphoric 

 acid. The sample of Adelie penguin guano compares very favourably with that of the 

 best-known guanos, as far as its agricultural value is concerned. Compared with 

 Peruvian guano, it will be seen that it is very little poorer in nitrogen, and contains 

 nearly double the amount of phosphoric acid. 



It approaches in composition the Ballestas guano, whose analysis is quoted above. 

 Its commercial value on the local market calculated from the most recent unit- 

 values for phosphoric acid and nitrogen (May 1912) would be about £5, 10s. per ton. 



