DRAININGS. 105 



manure, and from 3 cwt. of guano, with which he 

 manured three equal parcels of land, each an Eng- 

 lish acre in extent. 



1. Alteration of Urine by Continued 



Keeping. 



It is known that urine by long keeping (quickly, 

 however, at warm seasons of the year) acquires a 

 disagreeable, pungent odor, with an alkaline quality, 

 and that this putrid urine can be used in the same 

 way as soap, for washing and cleansing wool from 

 fatty and perspiratory substances, as happens, for 

 example, in the manufacture of cloth and in wool- 

 spinning. The volatile and alkaline body is gener- 

 ated in the putrefaction of the urine from its azotized 

 constituents (urea, uric acid, etc.), and is that which 

 has already been frequently spoken of under the 

 names oi putrid nitrogen or ammonia. 



Whoever will take the trouble of instituting a few 

 experiments of a very simple character, for which he 

 requires only a candle or a small spirit-lamp, a plated 

 spoon, and a few saucers or wine-glasses, may read- 

 ily make himself intimate with the properties of am- 

 monia, that extremely important nutrient of plants, 

 and draw from the results of his experiments very 

 profitable inferences for the rational treatment of 

 drainings. 



First Experiment. — Some litmus-paper must first 

 be prepared, which is needed as a test for the subse- 

 quent experiments. Put a small quantity of litmus 



