162 TALKS ON MANURES. 



30 cwt. (3,300 Ibs.) of hay per acre ; the other half was allowed to 

 grow six or seven weeks longer, and was then (October 8th), cut 

 for seed. The yield was a little over 5^ bushels of seed per acre. 

 Whether the clover allowed to grow for seed, was on the richer or 

 poorer half of the field, we are not informed. 



" Dr. Ycelcker then analyzed tiie soil. That from the part of the 

 fijld mown twice for hay, contained per acre: 



Fir.J six Second six Third six Total, 13. 



inches inches. inches. inches deep. 



Phosphoric acid 4,950 2,725 3,575 11,250 



Nitrogen 3,350 1,875 1,3:35 6,550 



"The soil from the part mown once for hay, and tfien for seed, 

 contained per acre : 



first s'.x Second six Third six Total, 18 

 inches. inches. inches. inches deep. 



Phosphoric acid 3,975 4,150 3,500 11,025 



Nitrogen 4,725 3,350 2/J25 10,300 



" Dr.Vcelcker also ascertained the amount Sind composition of the 

 clovcr-r0<?& growing in the soil on the two parts of the field. On 

 the ptrt mown twice for hay, the roots contained per acre 24|lbs. 

 of nitrogen. On the part mown once for hay, and then for seed, 

 the roots contained 51i Ibs. of nitrogen per acre." 



" Now," said the Doctor, " these facts are very interesting, but 

 there is no sort of evidence tending to show that the clover has any- 

 thing to do with increasing or decreasing the quantity of nitrogen or 

 phosphoric acid found in the soil." 



" There was more clover-roots per acre, where the clover was 

 allowed to go to seed. But that may be because the soil happened 

 to be richer on this part-ef the field. There was, in the first six 

 inches of the soil, 3,350 Ibs. of nitrogen per acre r on one-half of the 

 field, and 4,725 Ibs. on the other half ; and it is not at all surprising 

 that on the latter half there should be a greater growth of clover 

 and clover-roots. To snpposo that during the six or seven weeks 

 while the clover was maturing its seed, the clover-plants could 

 accumulate 1,375 Ibs. of nitrogen, is absurd." 



"But Dr. Vcelcker," said the Deacon, "states, and states truly, 

 that ' more leaves fall on the ground when clover is grown for 

 seed, than when it is mown for hay ; and, consequently, more nitro- 

 gen is left after clover-seed than after hay, which accounts for 

 wheat yielding a better crop after clover-seed than after hay.' " 



" This is all true," said the Doctor, " but we can not accept Dr. 

 Vcelckcr's analyses as proving it. To account in this way for the 

 1,375 Ibs. of nitrogen, we should have to suppose that the clover- 

 plants, in going to s?ed, slied one hundred tons of dry clover-leaves 



