744 



GUANO 



and recorded by all classes of writers on agricultural subjects. It has boon the means, 

 moreover, of converting the sandy desert around Lima into a soil capable of raising 

 abundant crops of maize ; hence the Peruvian proverb, ' Huano, though no saint, 

 works many miracles.' 



Commercial varieties. The following appear to be the chief: 



1. Peruvian. 



2. Augamos. 



3. Icliahoe. 



4. Patagonian. 



5. Saldanha Bay. 



6. Kooria Mooriu. 



7. African. 



8. Indian. 



Chemistry. Gruano being an article of so great value to the agriculturist as a manure, 

 and being liable not only to adulteration to a very great extent, but also varying when 

 genuine considerably in quality, it is highly important to have some means of ascer- 

 taining its value. This cannot be done satisfactorily by ever so experienced a dealer 

 by mere inspection, and therefore, both for the buyer and the seller, resort is necessary, 

 for a knowledge of its compound parts, to the analysis of the chemist. 1 Such being the 

 case, we must lirst ascertain the composition of genuine guano, and then inquire upon 

 which of its several constituents ite value as a manure depends. 



The following is one of the earliest analyses by Fourcroy and Vauquelin, of a sample 

 of guano presented to them by Baron Von Humboldt, showing the composition in 100 

 parts : 



Urate of ammonia 9'0 



Oxalate of ammonia 10 '6 



Oxalate of lime 7'0 



Phosphate of ammonia 6'0 



Phosphate of ammonia and magnesia . . . 2'6 



Sulphate of potash 5" 5 



soda 3-3 



Sal-ammoniac 4-2 



Phosphate of lime 14'3 



Clay and sand 4'7 



Water and organic matter 32'2 



But perhaps the constitution of guano is better exhibited by the following analysis 

 of three sorts by Denham Smith : 



Denham Smith. 



AMERICAN GUANO. Analysis of three 

 ] . Constituents soluble in hot water (in 100 parts of Guano'). 



2. Constituents soluble in cold water (in 100 parts}. 



Liebig's * Chemistry in its Applications to Agriculture and Physiology,' p. 272. 



