MANURE. 143 



207. This is a practical view of a practical sub- 

 ject. The nitrogen present in the manure expresses 

 its true value. This position is substantiated by the 

 experience of practical men. The experiments un- 

 dertaken by order of the Saxon and Prussian author- 

 ities, to ascertain whether the contents of the sewers 

 of the cities of Dresden and Berlin, could be applied 

 to fertilizing the barren lands in their vicinity, may 

 be offered to prove its correctness. These varied in 

 every form, and continued for a long period, prove 

 that if a soil without manure, yields a crop of three 

 for one sown, then the same land dressed with cow 

 dung yields 



7 for one sown, — with 

 Horse dung 10 " " 



Human manure 14 " " 



Now the nitrogen in these has been shown, taking 

 the minimum of nitrogen in the human, at 1 1-2 per 

 cent, is as 1 : 1*50 : 3, whilst the above numbers 

 are to each other as 1 : 1*43 : 2. 



Considering how varied is the composition of night 

 soil, and how much diluted by various mixtures, this 

 agreement is as near, as ought to have been expected, 

 in experiments whose objects were so totally different 

 from that of ascertaining the quantity of nitrogen in 

 each different manure. 



