232 PERUVIAN GUANO, ETC. [chap. 



rich deposit, containing ii to 15 per cent, of nitrogen; 

 but as that deposit became exhausted, the other islands 

 producing a poorer material were in turn drawn upon. 

 Of recent years it has been found that new deposits have 

 accumulated on the Chinchas Islands to such an extent as 

 to justify fresh workings, and accordingly a guano with 

 a very high percentage of nitrogen is again obtainable. 

 Another of the islands, Ballestas, has latterly been 

 yielding a very rich guano with more than 12 per 

 cent, of nitrogen and about an equal amount of 

 phosphoric acid, and now it is expected that material 

 of this class will always be available. 



It is difficult to form an adequate idea of the 

 enormous bird population of these islands and the 

 amount of food consumed during the breeding season, but 

 a recent commission which visited the islands estimated 

 the current production of fresh guano as 10,000 tons per 

 annum. Thus, freshly deposited guano is light grey in 

 colour and contains about 16 per cent, of nitrogen, with 

 9 of phosphoric acid, the usual brown colour coming as 

 the material ages and undergoes some decomposition. 

 A law has been recently passed ensuring a four- 

 months close season during the breeding of the birds, 

 and the Peruvian Government have recently forbidden 

 the working of the deposits during this close season in 

 order to ensure as little disturbance as possible. The 

 guano islands are now, in fact, being regularly " farmed," 

 and the exportations will consist of the previous years' 

 rich deposit, together with a certain amount of the older 

 accumulated stock. 



The bulk of the imports, however, consists of 

 material containing from 5 to 8 per cent, of nitrogen, 

 and each consignment is sold on the basis of an analysis 

 of a sample drawn by the officials of the Dock Company 

 as the vessel unloads. Another class of material has 



