334 MANURES. 



NOTE. The guano of the Lobos Islands is from 25 to 33 

 per cent, less valuable than the above. 



How to select a good article of guano. 



1. The drier the better there is less water to pay for and 

 transport. 



2. The lighter the color the better it is the less com- 

 pletely dissolved. 



3. If it has not a strong ammoniacal smell, it ought to 

 give off such a smell when a spoonful of it is mixed with a 

 spoonful of slaked lime in a wine-glass. 



4. When put into a tumbler with water and stirred well, 

 and the water and fine matter poured off, it ought to leave 

 but little sand or stones. 



5. When heated to redness over a fire or bright flame, 

 until the animal matter is burned away, the ash should 

 nearly all dissolve in dilute muriatic acid. 



6. In looking at the printed analysis (which almost all 

 dealers furnish), see that the per cent, of water is small ; 

 that the organic matter containing ammonia approaches to 

 50 or 60 per cent. ; that the phosphates do not exceed 20 per 

 cent., and the common salt and sulphate of soda do not ex- 

 ceed 5 or 6 per cent. Johnston. 



How to Apply Guano. From 200 to 500 Ibs. per acre is 

 a proper dressing, the largest quantity being required for the 

 more sterile soils. Mix it thoroughly for a few days with 

 five times its bulk of vegetable mould or loam and some 



