300 Dr Tschudi on Guano, 



During the first year of the deposit the strata are white, 

 and the guano is then called Guano bianco. In the opinion 

 of the Peruvian cultivators, this is the most efficacious kind. 

 It is found in the Punta de Hormillos, on the islands of Islay, 

 Jesus, Margarita, &c. 



As soon as the dealers in guano begin to work one of the 

 beds, the island on which it is formed is abandoned by the 

 birds. It has also been remarked, that since the increase of 

 trade and navigation, they have withdrawn from the islands 

 in the neighbourhood of the ports. 



Much has recently been written on the employment and 

 utility of guano ; but the manner in which it is employed as 

 manure in Peru, seems to be but little known. The Peruvians 

 use it chiefly in the cultivation of maize and potatoes ; a few 

 weeks after the seeds begin to shoot, a little hollow is dug 

 round each root, and is filled up with guano, which is after- 

 wards covered with a layer of earth. After the lapse of 

 twelve or fifteen hours, the whole field is laid under water, 

 and is left in that state for some hours. Of the Guano bianco 

 a less quantity suffices, and the field must be more speedily 

 and abundantly watered, otherwise the roots would be de- 

 stroyed. The effect of this manure is incredibly rapid. In a 

 few days the growth of the plant is doubled ; if the manure 

 be repeated a second time, but in smaller quantity, a rich 

 harvest is certain ; — -at least, the produce will be threefold 

 that which would have been obtained from the unmanured soil. 



The haciendas of the valley of Chancay have, during the 

 last fifty years, consumed annually 33,000 to 36,000 bushels 

 of guano brought from the islands of Chancha and Pisco. 



The price of the bushel of coloured guano is one dollar and 

 a quarter, and the price of the white from two to three dollars. 

 The price has recently undergone many fluctuations, in conse- 

 quence of the great exports to Europe. 



The employment of this kind of manure is very ancient in 

 Peru ; and there is authentic evidence of its having been used 

 in the time of the Incas. The white guano was then chiefly 

 found on the islands opposite to Chincha; so that for upwards 

 of six hundred years the deposit has been progressively re- 



