XII.] RICH AND POOR MANURE 235 



nitrogen, of which 70 per cent, was in an insoluble 

 condition, when the animals had been fed upon roots 

 and hay only. When, however, linseed and cotton cake 

 had been used in addition, the percentage of nitrogen 

 had risen to 082 per cent, of which less than half was in 

 the insoluble state. These two analyses refer to 

 manure taken straight from the boxes ; the next two 

 refer to manure made in exactly the same way, but 

 thrown out into the mixen and stored for a month to six 

 weeks before being analysed. It will be seen that where 

 roots and hay only had been fed, the manure then 

 contained much less total nitrogen, only 0-46 per cent, 

 though the amount of insoluble nitrogen is about the 

 same as before, thus showing that the losses had been 

 falling chiefly upon the soluble nitrogen. Where cake 

 has been fed the total loss of nitrogen due to storage had 

 also been great, and had again fallen upon the soluble 

 portions of the manure ; for whereas, in the fresh 

 manure more than 50 per cent, of the nitrogen was in 

 the soluble state, in the stored manure little more than 

 20 per cent, existed in that state. Thus the difference 

 between manure made by animals receiving concentrated 

 foods and those getting only roots and hay, lies chiefly 

 in the amount of ammonia and other soluble nitro- 

 genous substances the dung contains. This difference 

 is well seen in the effect of the manure upon the crops 

 grown with it. For example, it was found in the field 

 experiments made with the manures of which the 

 analyses have just been quoted, that whereas the manure 

 from the poorly fed animals brought about an increase 

 of crop amounting to about 30 per cent., the manure 

 from the richly fed animals gave an increase of over 80 

 per cent In the second year after the application, 

 however, both lots of manure gave much the same 

 return, the manure made from the animals receiving 



