AGRICULTURAL TEXT-BOOK. 309 



struction of the soil, the climate, the season, the mode of cul 

 tivation, the salts already contained in the earth, but especially 

 the period, mode, and form in vv hich a manure is applied, all 

 combine in influencing the final result. Theoretically, the val 

 ue of a manure depends upon the amount of nitrogen which 

 it contains, but-, practically, this does not always prove to be the 

 case ; and in some instances, a salt, such as gypsum, wholly de 

 void of nitrogen, may return a larger crop than any nitrogenous 

 manure we can apply. The rule, however, is general in its ap 

 plication, the exceptions comparatively few. The form of a 

 manure, and the way in which we apply it are, in practice, of 

 chief importance. Thus, in most instances, barn-yard manure 

 well prepared and well rotted, is very superior in action to &quot; long 

 dung,&quot; unfermented, and with the vegetable matter undecayed. 

 Yet there are soils and crops for which the latter is preferable. 

 Again, bones owe much of their efficacy to the manner in which 

 they are prepared. Whole bones, boiled bones, crushed or 

 ground bones, bones dissolved in sulphuric acid, and applied in 

 a powder, or in a solution with water, all differ in their effects 

 and profitable results. Thus, in an English experiment, it was 

 found that 



16 bushels of crushed bones gave 10 tons 3 cwt. turnips per acre. 

 2 &quot; bones dissolved in acid and applied dry gave 11 tons 15 cwt. 

 4 . 14 t , n 



8 16 i 



But when applied in a liquid form at the time of sowing, the 

 effect was still more remarkable, thus : 



Tons per acre, 



16 bushels of bone dust (dry) produced 11 of turnips. 



8 &quot; dissolved in 83 Ibs of acid dried up and ^ ,, (( 



sown with the hand produced 5 



While 2 bushels, with 83 Ibs. of acid, and 400 gal- ? T9l / 



Ions water produced /& 



And, again, in a third locality in Scotland, 76 Ibs. 

 of bones, 46 Ibs. of acid, and 400 gallons of 

 water produced 



Wiiile 410 Ibs. of bones, with 28 Ibs. of acid ap- ? ,- 

 plied dry, produced only $ 



