GUANO 



741 



mated at no less than 3,000,000^. But during the last few years the quantity 

 imported has somewhat diminished, and hence the rise in price from 111. to 111. per 

 ton. 



Our importations of guano since 1868 have been as follow : 



The conditions essential for the preservation of these excrements appear to be the 

 existence of a soil consisting of a mixture of sand and clay, in a country where the 

 birds are allowed to live for ages undisturbed by man or man's works, and where, 

 moreover, the climate is very dry, free not only from rain, but also from heavy dews. 



These conditions appear to have been combined to a remarkable extent on the coasts 

 of Peru and Bolivia, between latitudes 13 north and 21 south of the equator, for 

 although beyond this region the flocks of cormorants, flamingoes, cranes and other sea- 

 fowl, appear to be equally numerous, yet the excrement is rapidly carried away by the 

 rain or dew. 



It is then the dryness of the climate chiefly which has permitted the guano to accu- 

 mulate on these coasts, for, says Mr. Darwin ' ' In Peru real deserts occur over wide 

 tracts of country. It has become a proverb that rain never falls in the lower part of 

 Peru.' And again: 'The town of Iquique contains about 1,000 inhabitants, and 

 stands on a little plain of sand at the foot of a great wall of rock, 2,000 feet in keight, 

 the whole utterly desert. A light shower of rain falls only once in very many 

 years,' Indeed, since three-fifths of the constituent parts of guano are sohdaia in 



1 ' Researches in Geology and Natural History,' p. 421. 





