ON THE euANo, 323 



are frequented by a multitude of birds, particularly of the The place fre- 



fpecies of Ardea and Phoenicopterus, who roofl: there every numbers'^o/^'* 



right: but the excrements of thefe birds have hardly formed, birds. 



in three centuries, a layer of four or five lines in depth. Is 



then the Guano the efFe6l of fome convultion of the globe, 



like pit-coal and fofiil wood ? The fertiUty of the naturally Sterile foil of 



fteriie foil of Peru is derived from the Guano, which has be-^"" '"^'^'^'^"'*- 



ful by the 



come a material article of commerce. Fifty little vefTels, Guano. 

 called Guuneras, are conftantly employed in fetching this^°^^'^^'"P'°y«<i 



c i/-,ri/iT m ■ 1 to colled it. 



manure, tor the iupply ot the coalt. Its effluvmm may beit has a ftrong 



fmelled at the diflance of a quarter of a league. The failors o«i«"/ of am- 



accuftomed to this fmell of ammonia, feel no inconvenience 



from it; but we could not approach it without being affeded 



with continued fits of fneezing, 



" Maize is the particular vegetable for which Guano forms Maize particu- 



an excellent manure. The Spaniards learned its ufe of the J^"" ^ ^^"^^^^'^ 

 T 1- Tr > 1 , 1 -I • by Guano as a 



Indians: It too much be thrown upon the maize, the root iSmanurct 



burned and defiroyed. Guano is tooacidifiable, and is there- 

 fore a manure containing hydruret of azote; whilfl all other 

 manures are rather hydrurets of carbon. '* 



Guano is of a dirty yellow colour, rather Infipid to the its appearance* 

 tafte, but pofleffing a powerful odour, partaking of caftor and 

 of valerian. It turns black in the fire, and exhales a white 

 fmoke of an ammoniacal fmell. 



Its folubilily in water, particularly with potafli, determined Partly folublc in 

 the operators as to the method they fhould purfue in ilsanalyfis.^*^^* 

 They treated it fucceffively with water, with potafb, and with 

 muriatic acid; each of which methods prefented many phe- 

 nomena, as related in the following part of this paper, di- 

 vefted of the particular details of procefs, which are too ex- 

 tenfive for an exlradt. 



Ten grammes of this matter, after being repeatedly wathed The folution 

 with large quantities of boiling water, were reduced to 5yB '* ^'^'^* 

 grammes. The water had obtained a red colour, which it 

 communicated to paper ftained with turnfole. 



In diftillation, the water yielded ammonia during the whole The water 

 operation. Twenty-four hours afterwards, it had depofited a yielded ammonia 

 dirty yellow powder, pofleiling very little flavour, but with and depofited'a 

 an odour of calior : On the furface was a cryllalline pellicle, yel'ow powder 

 ,. , r 1 ■ I 1 1 rf • With a fmclJ of 



ot the fame colour with the depohtion. caftor. 



The 



