FERTILIZERS. 59 



able to furnish, as much, as the former, and the quality is not quite equal to that produced by 

 the Chincha, as will be seen from the following analysis of the two varieties compared : 



i. n. 



Chincha. Guanape. 



Nitrogen, 13.50 9.70 



Phosphoric acid, . . . . . 14.54 13.10 



Sand, 14.20 



Considerable quantities are also furnished by the Lobos, Macabi, and Ballistas islands. 



The Chincha Islands are peculiarly adapted to furnishing a fine quality of this material, 

 as they are located only about twelve miles from the coast of Peru, in a region where rain 

 never falls, and the air is so dry that the juices of meat will evaporate so rapidly that it can 

 be preserved by drying without salt. Therefore, the accumulations of the excrement deposited 

 there for ages by the sea-birds have never been leached of their valuable fertilizing properties 

 by the rains, and possess the elements suited to plant-growth in an eminent degree. These 

 islands are almost entirely devoid of vegetation, are very rocky, and covered to an incredible 

 depth with these deposits of the excrement of the sea-fowl, which gather there and feed upon 

 the fish that are so numerous in the waters surrounding their shores. It is said to look in 

 the distance, on approaching the islands, like light-colored hills covered with snow, so great is 

 the amount accumulated. It is, as will be seen by consulting the table giving the analysis of 

 manures on a previous page, very rich in nitrogen and phosphoric acid, and well adapted to 

 most crops and soils. No definite rule can be given with respect to what soils will be most 

 suited to its use, and hence the most benefited by its application, since soils differ so greatly, 

 that this can best be determined by experiment. 



If used too long, however, upon any soil without a change to some other manure for a 

 time, the soil will be liable to become exhausted of those elements that it does not largely 

 furnish. This is true of all fertilizers that do not furnish a fair proportion of all the elements 

 of plant-food. It is wonderfully stimulating in its effects when applied to old, exhausted 

 soils. Peruvian guano should not be applied in its pure state to seed of any kind, as it will 

 be liable to injure it. Some farmers recommend mixing it with three or four times its 

 weight in good soil before using. For such crops as grass, wheat, oats, etc., it should be 

 sowed broadcast in the early spring. For corn, potatoes, cotton, beans, peas, etc., the mixture 

 should be placed in each hill, covered slightly with earth, and the seed dropped upon it, thus 

 giving the opportunity of mingling its elem ents with the soil before the tender rootlets pene 

 trate it. It is best in all cases to apply it in damp weather ; in fact, its value is greatly 

 affected by the moisture or dryness of the season whenever used, an unusually dry or wet 

 season being injurious, as the former prevents decomposition, while the latter, in many soils, 

 especially sandy soils, leaches out its most valuable properties, and places them beyond the 

 reach of the plant-roots. The average quantity for uco is from two hundred to three hundred 

 pounds per acre. &quot;When applied to flowering plants and garden vegetables, it is well to dilute 

 it in water and sprinkle about the roots. 



Rectified Peruvian Oliano. For several years after the introduction of Peruvian 

 guano into the market, it continued to be of uniform quality; after a time, however, it was 

 observed that various admixtures of stones from the underlying rocks, and sand from beach 

 washings, showed that some portions of the supply were becoming exhausted. It also some 

 times happened that entire cargoes, or a portion of them, became damaged by sea- water in 

 the transportation, or by being packed in a very damp place. It was decided by parties 

 interested in the guano trade, to endeavor to restore the value thus lost by treating the 

 damaged material with sulphuric acid, by mixing from twenty to twenty -two pounds of the 

 acid with every one hundred pounds of guano when dried, which experiment was found to 

 be very successful, the rectified guano meeting with unusual favor, so much so that when the 

 damaged article was disposed of, the good guanos were subjected to the same process. 



