EXPERIMENTS ON CLOVER-SOILS. 161 



tainty of a good result, than such food can be applied to the land 

 in the shape of nitrogenous spring top-dressings." 



" Thank you Charley," s-rid the Doctor, " that is tlie most re- 

 markable paper I ever listened to. I do not quite know what to 

 think of it. We shall have to examine it carefully." 



" The first three propositions in the Summary," said I, " are un- 

 questionably true. Proposition No. 4, is equally true, but we must 

 be careful what meaning we attach ton he word ' accumulate.' The 

 idea is, that clover gathers up the nitrogen in the soil. It does not 

 increase the absolute amount of nitrogen. It accumulates it brings 

 it together." 



" Proposition Ho. 5, will not be disputed ; and I think we may 

 accept No. 6, also, though we can not be sure that allowing clover 

 to go to seed, had anything to do with the increased quantity of 

 clover-roots." 



" Proposition No. 7, may or may not be true. We have no 

 proof, only a * probability ; ' and the same may be said in regard to 

 propositions Nos. 8, 9, and 10." 



The Deacon seemed uneasy. He did not like these remarks. He 

 had got the impression, while Charley was reading, that much 

 more was proved than Dr. Vcelcker claims in his Summary. 



" I thought," said he, 4< that on the part of the field where the 

 clover was allowed to go to seed, Dr. Yrelcker found a great in- 

 crease in the amount of nitrogen." 



" That seems to be the general impression," said the Doctor, " but 

 in point of fact, we have no proof that the growth of clover, either 

 for hay or for seed, had anything to do with the quantity of nitro- 

 gen and phosphoric acid found in the soil. The facts given by Dr. 

 Vcelcker, are exceedingly interesting. Let us look at them : " 



"A field of 11 acres was sown to winter- wheat, and seeded down 

 in the spring, w r ith 12 Ibs. per acre of clover. The wheat yielded 

 40 bushels per acre. The next year, on the 25th of June, the 

 clover was mown for hay. We are told that ' the best part of the 

 field yielded three tons (6,720 Ibs.) of clover-hay per acre; the 

 whole field averaging 2 tons (5,600 Ibs.) per acre.' " 



" We are not informed how much land there was of the * best 

 part,' but assuming that it was half the field, the poorer part 

 must Have yielded only 4,480 Ibs. of hay per acre, or only two- 

 thirds as much as the other. This shows that there was consider- 

 able difference in the quality or condition of the land. 



" After the field was mown for hay.it was divided into two parts : 

 one part was mown again for hay, August 21st, and yielded about 



