Fish Guano 



Here are the approximate contents of good 

 average fish guano. 



Average Fish Guano, 



Moisture .. .. .. 17 per cent. 



Organic matter . . . . 60 ,, 



Phosphoric acid .. .. 7 ,, 



Lime .. .. .. 7 ,, 



Magnesia . . . . . . 4 ,, 



Various .. .. .. 5 ,, 



Contains Nitrogen N . . . . 7 ,, 



Corresponding to Ammonia 



InHs . . . . . . . . 8^ ,, 



Corresponding to tribasic 



phosphates of lime . . .. 15 J „ 



The finer the guano, the more it will be worth, 

 but in any case the value of the unit of nitrogen is 

 notably less in this guano than in the nitrate 

 of soda (NaNOs), or in sulphate of ammonia 

 [NH3(H2S04)]. The unit of phosphoric acid is of 

 equal value to that of bone phosphate, but never 

 has the value of the phosphoric acid in the super- 

 phosphates, which are monocalcic or dicalcic phos- 

 phoric acid. The potash is equal in value to 

 commercial potash. 



The guano of oily fish will be bought by the unit 

 at a slightly lower rate than that without oil. If 

 the prices are equal, preference should be given to 

 the latter. Fish guano is never a manure of rapid 

 action, because the nitrogen only exists in a form 

 of organic combinations, which are slow to decompose 

 and become assimilable. The same remark applies 

 to its phosphates, which are in a tribasic form. On 

 the other hand, it is not lost in the soil, and can be 

 applied a long time in advance, when its action will 



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