144 URINE. 



effervescence ceases, keeping it well stirred 

 during the whole of the time, and taking care 

 not to add an excess of acid. In this case the 

 ammonia unites at once with the sulphuric 

 acid to form the sulphate of ammonia ; and the 

 carbon, being disengaged, escapes in the state 

 of a gas. 



Other means might be used to effect the 

 same results as we have here demonstrated ; 

 but it is needless to specify them, as those we 

 have already detailed combine great facility as 

 well as extreme cheapness. 



Having thus specified the change that takes 

 place in the state of urine ; the best manner 

 for converting the ammonia for the purposes of 

 agriculture ; we shall suggest the best means 

 of practically using this manure on a farm. 



The first thing necessary is to procure a 

 supply of urine. But if due care is used to 

 save all that is now wasted, no farm need be 

 in want of it. 



The supply being obtained, it should be 

 placed in large casks or tanks, under cover, 

 until the volatile smell of the ammonia indi- 

 cates that decomposition has taken place. 

 When this occurs, it may be either poured 

 over a heap of compost, consisting of coal 

 ashes, charcoal, or gypsum, in any proportions 

 that are the most conveniently obtained, and 

 then allowed to dry, by frequently turning the 

 heap. Care being taken, that if any volatile 

 smell occurs, during this process of drying, that 

 more gypsum be at once added. The volatile 

 ammonia will in this operation be absorbed by 

 the gypsum, and converted into a sulphate of 



