13 



Subtracting from the 24,94 grams 14.74 grams, due to the after- 

 effect of 0.6 gram of superphosphate acid, there renuiin 10.2 grams 

 of increase of yield, due to the 0.6 gram of bone-meal acid, while from 

 the superphosphate acid an after-effect of (43.41 — 14.74) 28. G7 

 grams would be expected. 



c. 0.3 gram of superpliosphate acid with O.ti gram of bone-meal acid 

 gave an increase of yield of 19.8 grams. Subtracting from this 7.37 

 grams, due to the 0.3 gram of superphosphate acid, there I'emain 

 1 2.43 grams increase for the 0.9 gram of bone-meal acid. From a like 

 quantity of superphosphate acid an increase of 36.04 grams would 

 be expected. 



i\: Exactly the same is true of the largest application of phos- 

 phoric acid in which 1.8 grams, in the form of superphosphate acid, 

 produced an increase of 65.03 grams. 



We thus have produced by 0.3 gram of superphosphate acid with 

 1.5 grams of bone-meal acid an average yield increase of 23.62 grams. 

 Deducting 7.37 grams, for the eii'ect of the 0.3 gram of superphos- 

 phate acid, and 16.25 grams increase remain, for the effect of 1.5 

 grams bone-meal acid. The superphosphate acid would have given 

 an increase of (65.03 — 7.37 grams) 57.66 grams. 



0.6 gram of superphosphate acid with 1.2 grams of bone-meal acid 

 gave an average increase of yield of 26.74 grams ; from this subtract- 

 ing 14.74 grams, the increase of yield due to 0.6 gram of superphos- 

 phate acid, and 12.00 grams remain for the 1.2 gram of bone-meal 

 acid. But a like quantity of superphosphate acid would have 

 produced (65.03 — 14.74 grams) 50.29 grams. 



0.9 gram of superphosphate acid with 0.9 gram of bone-meal acid 

 gave an increase of yield of 35.08 grams ; taking from this 29.08, the 

 amount due to 0.!) giam of superphosphate acid 6.01 grams remain for 

 the bone-meal, while the same quantity of superphosphate acid would 

 have given (!lA_oi). 32.52 grams of increase of yield. 



However the combination may be made, with much or little bone- 

 meal, the effect is the same. No result can be produced, with oats 

 as a second crop, which w^ould not be approximately that of the 

 superphosphate phosphoric acid alone. 



In Table III are the figures for the after-crop of mustard i. e. the 

 third crop. The oats were harvested in the beginning of August, 

 the mustard, had no further application of phosphoric acid, but did 

 receive nitrogen and gave the following results : 



INCREASE OF YIELD OF GREEN MUSTARD. 



Grams. 



Phos. Acid applied. Superphosphate. Raw hone-meal. Glue-free bone-meal. 

 Grams. 



0.6 52.9 —0.3 +34.2 



1.2 173.9 —4.9 -1-15.2 



1.8 196.9 -1-85.2 -j-33.9 



