15 



Grams. Grams. 



0.571 With glue-free bone-meal 0.034: 



With Superphos, •{ 0.213 " raw " 0.007 



0.301 " steamed " 0.032 



Average 0.3G2 0.024 



Only 7 per cent of the superphosphate phosphoric acid taken up came 

 fi'om the bone-meal, the same quantities of phosphoric acid being 

 applied in each case. This result is strilvingly similar to Waguer's 

 statement concerning the effectiveness of bone-meals in the first year, 

 and also to the figures which were above given for sandy soils. Bone- 

 meal, therefore, behaves in loam soils as it does in sandy soils, in soils 

 rich in phosphoric acid as it does in those low in that acid. In each 

 case the bone-meal phosphoric acid failed to produce any important 

 effect. 



Series E. Table V. (1894.) 



To answer the question still more completely, mustard was raised 

 as a second crop, after barley, to ascertain whether, in the various 

 soils, an after-effect of the bone-meal phosphoric acid could be 

 noticed. The number of these experiments is somewhat greater than 

 those with barley, because several barley experiments were ruined by 

 attacks of the corn-fly. 



These, however, serve to show the after-efi'ect, and the results are 

 given in Table V. The increase of yield is shown as follows : 



With Superphos. 



Average 28.3 5.2 



In no single instance did the bone-meal phosphoric acid approxi- 

 mate in its effects that of the superphosphate. The same result 

 appears from figures showing the removal of phosphoric acid by the 

 crop. 



Phos. Acid, grams. Phos. Acid, grams 



0.209 with glue-free bone-meal 0.003 



With Superphos. ^ 0.199 with raw " 0.016 



0.170 with steamed " 0.026 



Average 0.19." 0.015 



The bone-meal phosphoric acid could accordingly produce only 

 7.7 per cent of the after-effect on plants which the superphosphate 

 acid produced (7 per cent with the first crop). 



