THE FAKMERS' KEGISTER. 



57 



Iquique, and on the hill of Pica. The <erm 

 ' gUcirio ol Iquique' is somelimes used from its 

 having been first procured (rom the island ol' ihai 

 name. 'I'liis island is situated about 400 yards 

 I'rom the port ol' lqui(]ue. It is about hall a mile 

 long, and about 200 yards broad ; and luriiished 

 large quaiiliiies of guano lor 25 years, when ii 

 became exhausted. The hill ol Pica is very high, 

 and is covered with guano down to the water's 

 edge ; while that side which does not lace the sea 

 id uf sand and gravel. In this hill or rock I am 

 jnlbrmed that a silver- mine was Ibrmerly worked, 

 but that no trace ol' guano was (bund during ihe 

 excavation. The adjoining hills on either side 

 are of eand, which is carried by the winds, and 

 covers up the guano ; to remove vvhich the sand 

 is first taken away, and deep excavations are 

 made ; the guano extending nearly a quarter of a 

 league in length, and 300 j/arJs in depth.* It is 

 likewise Ibund at St. Lobos, about three leagues 

 to the south of Pica ; but, as the anchorage is 

 dangerous, little business ia done here." 



Origin of the guano. — The extraordinary 

 thickness and extent of these deposiles ofguano 

 eeem ai first sight to throw discredit on the state- 

 ment that it is altogether derived /rom the dung 

 of the countless flocks of sea-fjwl which frequent 

 the islands and rocks of the Peruvian shore; yet 

 the evidence on this point is perfectly satisfactory. 

 The living birds still deposiie the white guano on 

 the islands to which they resort. In the isles 

 of Islay and Jesus 20 to 25 tons of this recent 

 guano are occasi)naiiy cullecied in a sinirle seasoi'. 

 In tlie island of Torrecilla the white may be seen 

 changing into the red variety (Wmierleldt ;) 

 wliilo, in the midst of the great accumulations of 

 the latter kind, bones and leathers (Frezier) of 

 birds are found, as if to remove any doubt which 

 might still remain as to its origin, lis real origin, 

 indeed, was well known to the government of 

 the Incae, and its national importance fully un- 

 derstood. It was made a capital cffisnce to kill 

 the young birds on the guano islands. Each 

 island had lis overseer ; and as the whole coast 

 from jfrica to Chaucay, a distance of 200 leagues, 

 was manured almost entirely with guano, each 

 island was assigned to a special district of the 

 main land, and its produce was conveyed to that 

 district alone. (Humboldt.) 



It was not till the arrival of the Spaniards thnt 

 the original source of the guano was lor a time 

 doubted ; yet, when we consider how great a 

 lapse- of lime it n)ust have required to admit of 

 the accumulation of the extensive beds of ancient 

 guano still known to exist, we cannot wonder 

 that early European visiters should have receiv. 

 ed wiih hesiiaiion what we now readily admit 

 88 the true account of its origin. Of late years 

 the increase of traffic on the coasts has disturbed 

 or driven away the birds, and thus materially 

 diminished in many localities the annual produce 

 ol the while or recent guano. " Since the open- 

 ing of the port of Islay the birds have nearly de- 

 eeried the adjacent inlets." (Winterleldt.) 



It may be further added on this point that the 



• Mr. 'Winterfeldt can scarcely mean that the layer 

 of guano is actually 900 feet in thicknes5 : it probably 

 climbs up the mountain side so high. Pica and Iqui- 

 que are both within the latitude of 21° S., the limit 

 assigned by Humboldt. 

 Vol. X.-8 



chemical constitution of guano has been found 

 to be exactly such as is to be expected from the 

 above account of the mode of its production. 



Why, it may be asked, does thia substance 

 accumulate within the eight degrees of latitude 

 above staled only, though ihe sea-lbwl are said 

 equally to abound beyond these limits? This 

 question involves a consideration both of the 

 chentical nature of the substance itself and of the 

 physical condition of the country in whiiih it ac- 

 cumulates : it will be more naturally discussed, 

 therefore, in a subsequent section. 



Effects of guano on vegetation. — It is known 

 to have been a common practice to manure with 

 guano as lar back, at least, as the Iwellth century ; 

 and the possibility of raising crops on the sandy 

 plains of Peru is said to depend altogether on 

 the application of this substance.* (Humboldt.) 



" In a soil of remarkable sterility, composed 

 only of white sand and clay, it is sufficient to add 

 a small quantity of guano to be able to reap the 

 richest harvests of maize." (Boussingault.) 



" It has been calculated that fi-om 600 to 700 

 tons are annually sold in the port of Mollendo, for 

 the use ofthe country around the city of Arequipa. 

 In the province of Taracapa, and in the valleys of 

 Tambo and Victor, the consumption should be 

 something more ; as wheat, all kinds of fruit-treea 

 and plants, with the single exception of the su- 

 gar-cane, are manured wiih the guano : which is 

 not the case with the district of Arequipa, where 

 maize and the potato alone require it. In the 

 district of Arequipa 3 cwt. of the guano is spread 

 over an extent oi' 5000 square yards ;t but, in 

 Taracapa and the valleys of Tambo and Victor, 

 5 cwt. are required. The land thus manured in 

 Arequipa produces 45 for 1 of potatoes, and 35 

 for 1 of maize ; where wheat, manured with 

 horsR-dimg, produces only 18." (Winterfeldt). 



In 1828 the annual consumption of white and 

 brown guano in Peru was estimated at 600 or 700 

 tons in all ; but this is probably now much below 

 the truth. 



These facts afford sufficient evidenec of the 

 value of this substance as a manure in the soil 

 and climate of Peru. It has recently, however, 

 been imported in large quantities into this country, 

 and has already been tried upon various crops and 

 soils, and with highly satisfactory results. Seve- 

 ral of these results have been obligingly communi- 

 cated to me ; and, as the subject is an interesting 

 one to the agriculturist, I shall insert them in the 

 words of my several correspondenis. 



1. Experiment of Mr. Pusey. — "The guano 

 was applied, in the beginning of July, to half an 

 acre of ridged Swedes, at the rale of 3 cwt. to 

 th" acre, drilled under the seed. Bones, Poite- 

 vin's manure or night-soil, duntr. urate, and peat- 

 ashes, were applied at the same time on neighbor- 

 ing pieces of ground. The first action of the 

 guafl^ivas discouraging ; for, on one half of the 

 grouna dressed wiih it, no plant came up. On 

 trans lanting into the blank spaces, the seed was 

 found encrusted with the guano, without any sign 

 of vegetation. This ill effect might be easily 



• 'We have seen how it was prized by the ancient 

 Peruvians. About Villacori this people also manured 

 with a species of small fish, taken in great abundance 

 on the coast. 



t 4840 square yards mak« aia English acr« 



