132 NATUKAL MANURES. VI. 



He gives as an estimate of the quantities produced by each 

 bird per year pigeon, 6ft>.; hen, 12ft>.; duck, 18UX; goose or 

 turkey, 25H). 



Ulrich* gives the following as the average percentage com- 

 position of the dung of poultry : 



Pigeons. Fowls. Ducks. Geese. 



Water ... ... 62 65 53 82 



Organic matter ... 3132 2126 40 14 



Nitrogen ... ... 1-22-4 0-71-9 0-8 0'6 



Phosphorus pentoxide... 3-04-2 5-0 3-5 0'9 



Alkaline salts ... 2-02-2 1-21-6 0-4 3-1 



Ash ... ... 67 9^-14 7 4 



He estimates the annual production at 



Pigeons ... 2-5 kilos or 5'6R). per head 



Fowls ... 5-5 ,, or 12-4R). 



Ducks ... 8-5 or 19-lffi. 



Geese ... 11-0 ,, or 24-8R). 



and recommends that the manure be mixed with water con- 

 taining sulphuric acid (30R). of acid to Icwt. of manure), in 

 order to prevent loss by volatilisation of ammonia. 



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 w r ith water to 

 be very valuable except locally, A deposit of this character 

 from the coast of Ireland, examined by the author, contained, 

 in the damp sample, 47'5% water, 1-25% nitrogen, and 8-5% 

 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 Parisf, contained 



Water ... ... 18-02% 



Nitrogen ... ... 3-00 ,, 



Ash ... ... 52-87 ,, 



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



* Bieder. Centr. 1900, 3 ; Jour. Chem. Soc. 1900, abst. ii., 308. 

 t Annales Agronomiques, 1897, 47. 



