PRACTICAL AGRICULTURE. 39 



them should be thrown away ; and reservoirs are placed 

 in every house, where they are collected with the utmost 

 care. No other kind of manure is used for their grain- 

 fields. 



Human urine contains a greater variety of constituents 

 than any other species examined. Urea, uric acid, and 

 another acid similar to it in nature, called rosacic acid, 

 acetic acid, albumen, gelatine, a resinous matter, and 

 its various salts, are all valuable to the land, inasmuch 

 as from the land they or their elements have been origi- 

 nally derived. The urine of animals that feed exclusively 

 on flesh, contains more animal matter, and consequently 

 more nitrogen, than that of vegetable feeders — whence 

 it is more apt to run into the putrefactive process, and 

 disengage ammonia. In proportion as there are more 

 gelatine and albumen in urine, so in proportion does it 

 putrefy more rapidly. Thus, then, all urine contains 

 the essential elements of vegetables in a state of solu- 

 tion ; and that will be the best for manure which con- 

 tains most albumen, gelatine, and urea. Putrid urine 

 abounds in ammoniacal salts, and is only less active 

 as a manure than fresh urine, because of the portion of 

 ammonia which is continually exhaling into the atmos- 

 phere. 



As to the urine of cattle, it contains less water than 

 that of man, varying with the kind of food on which the 

 animal is fed. A cow will secrete and discharge from 

 two thousand to three thousand gallons of urine a year; 

 and this quantity will contain at least from 1200 to 

 1500 pounds of dry solid saline matters, worth from fifty 

 to sixty dollars. 



The urine of the cow is particularly rich in salts of 

 potash, but contains very little soda. The urine of swine 

 contains a large quantity of the phosphates of ammonia 

 and magnesia. That of the horse contains less nitrogen 

 and phosphates than that of man, 



The fertilizing powers of animal manures, whether 

 fluid or solid, is dependent, like that of the soil itself, 

 upon the happy admixture of a great number, if not of 

 all, those substances which are required by plants in the 



