24 ON EXPERIMENTS WITH GUANO. [Appendix 



red-top yellow, in a field of rather stiff soil, were benefitted, the former yielding 

 i more produce in weight, and the latter | more weight. Wm, Fleming. 



''Barochcm, 26th October, 1841." 



Note.— The price.s paid by Mr. Fleming were as follow :— Bone dust (fine) Is. 9d. per bushel ; 

 sulphate of ammonia (in crystals) 28s. per cwt. ; potash (very impure) 24s. per cwt. ; sulphate 

 of soda (in crystals) 6s. per cwt. ; nitrate of soda 22s. ; and sal-ammoniac 60s. per cwt. 



No. IV. 



SUGGESTIONS FOR COMPAHATIVE J^XPERIMEXTS WITH GUANO 

 AND OTHER MANURES. 



Guano is the name given in South America to thedvmg of the sea fowl which 

 hover in countless flocks along the shores of the Pcicific, and which, from time 

 immemorial, have deposited their droppings' on the rocks and the islands which 

 arc met with along the coast o. Peru. 



Besides the fresh white guano wliich is deposited year by year in these locali- 

 ties, there exist, in some spots, large accumuhuionsmore or less buried beneath 

 a covering of drifted sand, which have been thus buried and partially preserved 

 from an unknown antiquity. This ancient guano is of a brown colour, more or 

 less dark, and forms layers or heri[)s of limited extent, but which are said some- 

 times to exceed even (50 feet in thickness. 



In the :ime of the Incas this substance was known and highly valued as a ma- 

 nure, — the country along the coast for a length of 200 leagues was entirely ma- 

 nured by it, — the islands on whtcli it was formed were carefully watched and 

 preserved, — and it was declared to be a capital of!ence tokill any of the sea fowl 

 by which it was deposited. Ever since that time it has been more or less em- 

 ployed for the same purpose, and much of the culture now practised on this 

 thinly-peopled coast is entirely dependent for its success, if not for its existence, 

 on the stores of manure which the sea fowl thus place within reach of those parts 

 of the country which are susceptible of cultivation. 



In modern times, hov»-ever, the access of foreign shipping, and the want of 

 careful protection, have driven away many of the sea fowl, and lessened to a very 

 great degree the production of the recent guano. Thus tlie country is more de- 

 pendent than in former times on the more ancient deposits, which are now assi- 

 duously sought for, and when discovered beneath the sand, are carefully exca- 

 vated and transported to the sea-ports for sale. 



The dung of birds of all kind-'^, when exposed to the air, gradually undergoes 

 decomposition, gives off ammonia, and acquires a brown colour. As this am- 

 monia is one of the most fertilizing substances it contains, it will be readily un- 

 derstood that the old brown guano is much less valuable as a manure than that 

 •which is recent and white ; hence the care of the ancient Peruvians in collect- 

 ing the fresh, and their comparative neglect of the ancient guano. ' 



When the brown guano is put into water, a large quantity of it — sometimes 

 70 per cent, of the wliole — is dissolved. Hence, it is, because the climate of 

 Peru is so dry and arid that in the plains rain scarcely ever falls, that the guano 

 can accumulate as it is found to do. North and soudi of this line of coast, 

 where rains are less unfrequent, such accumulations are not met with, though 

 the birds appear equally plentifvd, and it may be safely stated that, had the cli- 

 mate of Peru been like that of England, the rains would have washed the guano 

 from the rocks almost as rapidly as it was deposited. 



Of the brown guano several cargoes have lately been brought to England by 



