EXPEEIMEXTAL STATIONS — REPORT FOR 1880. 



369 



The increase per acre in the amount of ash and woody fibre 

 produced on the dissolved phosphate plots at Harelaw is about 

 20 per cent, over that produced on the undissolved phosphate 

 plots, while at Pumpherston the increase amounts to 30 per cent. 

 The increase at Harelaw is normal ; that is to say, it is propor- 

 tionate to the total increase of the crop, while that at Pumpher- 

 ston is in excess of the normal proportion. 



The woody fibre was estimated in the ordinary way, which 

 consists in treating the dry turnip matter with a boiling 5 per 

 cent, solution of acid and alkali, and considering the insoluble 

 residue as composed of the woody fibre and a certain amount of 

 ashy matter, which is estimated and deducted so as to give the 

 woody fibre p)roper; but though this is the recognised and 

 generally adopted method, it is certain that it furnishes only an 

 approximation to the true amount of indigestible woody fibre. 

 For the purposes of comparison, however, it is quite reliable, and 

 in the present investigation it is relative and not absolute quan- 

 tities with which we are concerned. The amounts of ash and 

 woody fibre added together give the total amount of indigestible 

 material contained in the dry matter of the turnips, and the 



2 a 



