118 DRAININGS. 



mass is kept moist by frequent affusion or sprinkling 

 of urine, very considerable quantities of the latter 

 may be gradually brought to a dry form ; inasmuch 

 as the watery portions of the urine by degrees evap- 

 orate, and the ammoniacal combinations generated 

 by its nitrogen are firmly held and absorbed, partly 

 by the acids which are simultaneously formed in the 

 humus, and partly by the earth. A part of the nitro- 

 gen occasions at the same time the production of 

 nitric acid salts, which are not volatile. By occa- 

 sionally stirring up the heap, this process is very 

 essentially accelerated. Should a pungent odor of 

 ammonia be remarked, some sulphuric acid diluted 

 with water should be poured on, or some gypsum 

 added to the heap. In this mode of using drainings, 

 also, their previous admixture with sulphuric acid 

 has proved very serviceable. Beyond all doubt, by 

 the accumulation of such heaps of compost upon 

 every farm, considerable advantages may be secured, 

 since they furnish an external motive and obligation 

 for the retention and employment of many sub- 

 stances, which, in conformity with general custom, 

 are often thrown away. 



4. The practice adopted in many farming estab- 

 lishments and districts, of suffering the manure to lie 

 under the stock, is, so far as the drainings are con- 

 cerned, exceedingly beneficial, since in this case they 

 are for the greater part absorbed and retained firmly 

 by the straw, as will be more particularly explained 

 in the following chapter. The same remark applies 



