AVERAGE PRODUCE PER ACRE. 



121 



in order further to facilitate comparison, the figures representing 

 the total ash constituents of each crop may be brought together. 

 as here subjoined. By "dry matter" is, of course, meant the 

 whole mass of organic and inorganic substances which remains 

 after deduction of the water that can be separated at 212° Fahr. 

 With respect to the amount of water in the cereal and pulse 

 crops, we have relied chiefly on the authority of Messrs. Way 

 and Ogston, and with respect to turnips, partly on the same 

 authority, together with that of Lawes and Gilbert. It seems 

 probable that the results obtained by these gentlemen represent 

 more closely the crops of this country than those of the conti- 

 nental analysts. These latter seem to give the water in grain 

 and straw about 1 or 2 per cent, higher than we have taken it. 

 The percentage of water in turnips varies — as is well-known — 

 considerably, namely from 88 to 92, or even occasionally to 93. 

 We have taken 91 per cent, as a fair average. We append a 

 line giving the dry matter, &c., of ten tons of well- rotten farm- 

 yard manure. 



Dry Matter (at 212°) in whole Crops, Tops, and Straw, 

 WITH Ash, &c., per Acre. 



Here we observe a general accordance in the cereal crops with 

 respect both to the nitrogen and the valuable ash constituents. 

 But in the root crops, while there is a considerable increase 

 (about 1000 lbs.) of dry matter, there is a great increase of 

 nitrogen, phosphoric acid, and magnesia, with an enormously 

 increased amount of pota.sh, and, in the case of turnips, a still 



