GUANO. 131 



**The coloured Guano passes to the grajr; 

 has a rather strong am moniacal odour, and is 

 heavy ; dissolves in acids with effervescence; 

 a certain quantity being dissolved in water im- 

 ports an odour similar to that of urine; its fla- 

 vour is saltish and pungent; it gives precipitates 

 with ammonia, the oxalate of potass, the nitrate 

 of silver, with the subcarbonate and prussiate 

 of potass. The solution being evaporated, 

 cubic crystals of muriate of soda, and of muri- 

 ate of ammonia are left, kept for some days it 

 undergoes no alteration, and only acquires a 

 strong smell and taste. The Guano being cal- 

 cined, ammoniacal vapours are given off in 

 abundance, leaving a very light carbon. Four- 

 croy and Vauquelin met with uric acid, in part 

 saturated with ammonia and potass, phosphoric 

 acid combined with the same basis and wnth 

 lime, small quantities of the hydrochlorates of 

 ammonia and potass, a small quantity of fatty 

 matter, and of quartzy and ferruginous sand. 

 But in an analysis which the writer of this pa- 

 per has recently made, he found it to contain a 

 considerable quantity of the muriate of soda, of 

 ammoniacal salts, and of iron. The white 

 Guano is of the same composition, except that 

 it is free from sand, has not so powerful a smell 

 (from not having undergone spontaneous de- 

 composition) is lighter, leaves more residue in 

 the crucible, and contains a small proportion of 

 iron and muriate of soda. 



*'The date of the discovery of the Guano, 

 and of its introduction as a manure in Peruvian 

 agriculture is unknown, though no doubt ex- 

 ists as to its great antiquity. In many parts of 



