746 



GUANO 



Valuable as these elaborate analyses arc in a scientific point of view, they are quito 

 nniHoessary for practical purposes in ascertaining the value of any given sample, for 

 on which of these various constituents does the chief efficacy of guano depend ? 



Ammonia. Undoubtedly one <>f the ,nnst, if not the most, important constituents of 

 guano is the ammonia. Authors differ as to the precise manner in which ammonia 

 and its salts act in promoting the growth, and especially in the development of tin; 

 nitrogenisod compounds of plants ; but the fact is placed beyond dispute, whether it 

 bo that the ammonia contained in the air is decomposed by the leaves, or that the. salts 

 of ammonia are absorbed by the spongiolos of the roots in solution in water. Now, it 

 is quite possible that, in the mysterious economy of the life of the plant , the ammonia 

 may perform a slightly different function when in different states of combination, 

 either with hydrochloric, sulphuric, nitric, phosphoric, carbonic, uric, humic, or oxalic 

 acids ; and although, as a general rule, we should be inclined to yield the palm in point 

 of utility to the more soluble combinations, yet all experience goes to show that the 

 value of an ammoniacal manure may be measured chiefly, if not entirely, by the quantity 

 of that compound present, and is in a great measure independent of its state of 

 combination. 



The amount of ammonia corresponding to the total quantity of nitrogen in the 

 several varieties of guano ranges as follows: 



So that the average quantity of ammonia in the several varieties is 



Peruvian 

 Angamos 

 Ichaboe 



17 per cent. 



20 



7 



Patngonian . 

 Saldanl 

 Kooria Mooria 



2-/i per cent. 



1-5 



0-25 



1 'On the Composition and Money Value of the different kinds of Guano.' By S. Thomas Way, 

 &c. Journal of the Agricultural Society of England/ p. 202, &c. 



