COMPARISON OF MANURES. 205 



charging all the cost of a commercial manure to, and in expecting 

 to get our monej- back from, its nitrogen, phosphoric acid, and 

 potash ; the rest of the ingredients must be thrown in gratis, as of 

 no value generallj', although there may be cases where one or 

 another of them may be of some service. All of these matters the 

 stable manure also contains in abundance. 



So far no one can claim an3-thing for the stable manure that is 

 not supplied by the commercial fertilizer. The onl}' respect in 

 which the two materials are distinctly unlike is this : the stable 

 manure is composed largel}' of dead vegetable and animal matters 

 in process of decaj' ; the product of this decay is the humus or 

 vegetable mould of the soil. About one-fifth of ordinaiy stable 

 manure is made up of this vegetable and animal matter, while 

 not over six to eight thousandths is potash, five or six thousandths 

 nitrogen, and three thousandths phosphoric acid. Of nitrate of 

 soda, so much mentioned as a very useful fertilizer for its nitrogen, 

 one-sixth is this nitrogen. Of a good superphosphate, as this 

 fertilizer averages in this countrj', about one-eighth is phosphoric 

 acid ; and if one desires it, and is willing to pay for it, he can 

 have a superphosphate with one-third its weight of phosphoric 

 acid ; of a German muriate of potash from a third to a half maj' 

 be potash. But in all these materials there is no vegetable mat- 

 ter, and little or no animal matter. 



Here, then, is a clear distinction between the two kinds of manure, 

 the stable and the artificial : the stable manure has its few thou- 

 sandths of nitrogen, of phosphoric acid, and of potash, and its 

 one-fifth of decaying vegetable and animal matter ; the commer- 

 cial manure onl}' its few thousandths or even less of animal matter, 

 and its proportions of nitrogen, phosphoric acid, and potash counted 

 b}' eighths to thirds. About three-fourths of the stable manure is 

 only water, however ; expel this, and get a manure as dry as com- 

 mercial manures ordinarily are, and the comparison between the two 

 will be more just and no less striking ; we shall then see that four- 

 fifths of this dr}' manure is decaying vegetable and animal matter, 

 about one-fortieth is potash, one-eightieth phosphoric acid, and 

 one-fiftieth nitrogen. 



Can any way^ be now shown in which this striking difi^erence 

 between the two kinds of manure may account for the greater 

 measure of success that is attained in general with the stable 

 manure ? 



As already said, decaying vegetable or animal matter in the soil 



