178 



GUANO. 



An adulterated guano brought to us two years 

 ago from England contained but 7 per cent, of com- 

 bustible substances, with | per cent, of nitrogen, and 

 89 per cent, of ash (of a yellowish-brown color) ; this 

 latter being made up of 72 per cent, of silica, sand, 

 clay, and stone : here, therefore, one part of Peru- 

 vian guano was mixed with from six to seven times 

 the same quantity of clay and sand. Another lot 

 which arrived this spring (1851) at Hamburg from 

 England, in order to be sold to the good Germans, 

 consisted of one third part good Peruvian guano, 

 and two thirds fine sand ; upon combustion, it fur- 

 nished in like manner a brownish-red ash. 



Of the above-mentioned constituents, nitrogen 

 must be considered by far the most valuable ; for it 

 is this ingredient that imparts to guano that won- 

 derfully strong forcing power, for which it is so high- 

 ly prized and so dearly purchased. In the fresh 

 excrements of the birds, nitrogen is contained prin- 

 cipally in the form of uric acid, in precisely the same 

 way as in the urine of cows, sheep, etc.; on the 

 other hand, in the putrefied bird manure, as found 

 in the guano, the uric acid has been already con- 

 verted, as in putrid urine, into ammonia^ or, to speak 

 more accurately, into ammoniacal salts, which are 

 readily soluble and digestible by plants. We are, 

 therefore, to look upon guano as a manure that has 

 undergone complete putrefactive fermentation, — as 

 putrid drainings in a solid form ; and it is owing to this 

 circumstance that it attains its end so quickly, and 



