VI. MANURING AND GENEEAL MANUEES 123 



Pigeons 2-5 kilos or 5-6 Ib. per head. 



Fowls 5-5 12-4 



Ducks 8-5 19-1 



Geese 11-0 24-8 



and recommends that the manure be mixed with water containing 

 sulphuric acid (30 Ib. of acid to 1 cwt. of manure), in order to prevent 

 loss by volatilisation of ammonia. 



The excreta of wild animals and birds are sometimes found in 

 sufficiently large accumulations to be of importance. Those of car- 

 nivorous birds are particularly rich in nitrogen (largely due to their high 

 content of uric acid, which itself contains 33 per cent of nitrogen). 



A sample of the excrement of the S. African vulture collected in 

 the Orange River Colony, was examined by the author and found to 

 contain 



Moisture 



1 Loss on ignition 



Insoluble matter 



Lime 



Potash 



Phosphorus pentoxide 



Not determined 



2-26 per cent. 

 81-19 

 6-72 

 0-79 

 2-43 



2-14 



100-00 



Such products are extremely valuable as manure, for their nitrogen 

 is probably readily available. 



Deposits of the dung of sea-birds occur at places on the coast, 

 sometimes in sufficient quantities to be important. The material is 

 rich in nitrogen and phosphoric acid, though in ordinary climates 

 somewhat too heavily charged with water to be very valuable, except 

 locally. A deposit of this character from the coast of Ireland, ex- 

 amined by the author, contained, in the damp sample, 47*5 per cent 

 water, 1-25 per cent nitrogen and 8'5 per cent phosphoric acid. 



Bats' guano. Deposits of this substance are found in caves in 

 tropical climates, occasionally in sufficient quantities to be useful as 

 manure. Its composition varies considerably. A sample from Eboli, 

 Salerno, analysed by Paris,' 2 contained 



Water . 18-02 per cent. 



Nitrogen 3-00 



Ash 52-87 



The ash contained, in each 100 parts, 2 of potash, 13'8 of lime, 

 20 '7 of phosphorus pentoxide, and a small quantity of copper. The 

 nitrogen was almost all as nitrates. An American analysis 3 gives as 

 the composition of bats' guano 



Water . . 40-0 per cent. 



Nitrogen 8-2 ,, 



Potash 1-3 



Phosphorus pentoxide ..... 3-8 ,, 



1 Containing nitrogen, 25-27 per cent. 2 Ann. Agron., 1897, 47. 



3 Bull. 15, U.S. Dept. of Agric., 1893. 



