GUANO. 181 



good bird-manure, that, in examining for agricultural 

 purposes, they may be wholly omitted. The last 

 two deserve especial consideration only when they 

 occur in greater abundance ; for in this case they 

 must be regarded as used, on account of their low 

 price, for adulterating guano. As a guano so adul- 

 terated by soda salts, that marked above as No. 4, 

 and as a guano adulterated by gypsum, that repre- 

 sented as No. 6, may be pointed out. 



2. Operation and Employment of Guano. 



On account of the great abundance of easily di- 

 gestible nitrogen, that is, ammonia, in guano (only, 

 however, in the good), it must be deffe-med the most 

 forcing and most rapidly efficacious manure at the 

 command of German agriculture. For this reason, 

 it is above all others adapted for auxiliary ma- 

 nuring. In it the farmer possesses an excellent 

 means of improving common stable-muck, and in- 

 creasing its effect. Stall-manure is poor in nitro- 

 gen, for one load contains scarcely more of this 

 element than half a hundred-weight of guano. 

 This nitrogen is again incapable of being taken 

 immediately as food by plants, for it has not yet, 

 or at all events only in very trifling proportion, un- 

 dergone putrefaction ; it becomes gradually fit for 

 vegetable nutriment by lying in the earth. Here a 

 small addition of guano will produce an extraordi- 

 nary effect ; inasmuch as by its instrumentality 

 nourishment is furnished to young plants, until a 

 16 



