VIII.] IMPORTATIONS OF GUANO 231 



received, the more will it have lost nitrogen and the 

 richer will it have grown in phosphoric acid, until from 

 the material described above deposits are formed con- 

 taining little or nothing beyond phosphate of lime. 



The analyses (Table LXXVII.) will show how great 

 is the range in quality that thus results. 



Peruvian Guano. — Peruvian guano is derived from 

 three groups of islands off the coast of Peru, of which 

 the most important, Chinchas, is a little south of Callao. 

 The fertilising value of the deposit was known long 

 prior to the Spanish occupation of the country, in many 

 parts of which crops could only be obtained by the aid 

 of guano. 



A. von Humboldt was the first European to call 

 attention to the use of guano ; he brought samples 

 home with him about 1804, at which time he found 

 some fifty vessels annually employed in carrying guano 

 from the Chinchas Islands for use in Peru. 



The exportation to Europe, however, did not begin 

 until nearly forty years later, the first crops being landed 

 in Liverpool early in 1840. The success of the manure 

 was rapid and the exportation soon assumed consider- 

 able dimensions, as much as 283,300 tons reaching the 

 United Kingdom in 1845. For some time the annual 

 consumption remained at a very high figure, but 

 financial troubles, the war between Peru and Chili, the 

 exhaustion of the richest deposits, and difficulties 

 induced by adulteration and the natural variation in the 

 composition of the cargoes, led to a slackening in the 

 demand. During the last few years the exportation 

 has been at the rate of about 60,000 to 70,000 tons per 

 annum, of which the United Kingdom consumed about 

 one-half. 



During the earlier years Peruvian guano was derived 

 from the Chinchas Islands only, and was an exceedingly 



