XII.] COST OF FARMYARD MANURE 247 



the ton by the time it is ready to go on the land ; the 

 difference in price representing a real difference in value, 

 according to whether much concentrated food has been 

 consumed during its manufacture or not. The farmer, 

 then, who is faced with the problem of specially making 

 farmyard manure, or on the other hand, buying artificial 

 fertilisers or town dung, ought to reckon that such 

 manure of fair quality will cost about lOs. a ton to 

 make. In experiments dealing with fertilisers, this 

 figure should be taken as an average valuation of well- 

 made farmyard manure. It is noticeable also that if 

 we proceed to a valuation of farmyard manure on the 

 basis of the fertilising constituents it contains at the 

 usual unit rates, its price would work out to about 

 the same figure of los. a ton. 



