Proceedings of Seventeenth Xormal Institute 139 



The data of Table IV show that after being subjected to seven 

 months of leaching by winter rains, there was still more residual 

 carbonate of lime from the application of ground limestone than 

 was found from the more active finely divided carbonate applied, 

 and that formed from the carbonation of burnt and hydrated 

 lime, though none of the latter was leached prior to analysis. 

 Here, again, one may say. Is this not conservation? On the 

 contrary, jSTo; for, when dealing with an acid soil and the 

 usual lime applications, the beneficial results come from the lime 

 which reacts with the soil to neutralize lime requirement, and not 

 from that which is leached away and lost. This raises the ques- 

 tion as to the doubtful value of lumps of limestone remaining in a 

 soil which is acid. 



Physical betterment occurs in speed and extent in proportion 

 to the solubility of the carbonate. Hence, we sometimes secure 

 physical betterment more extensively from burnt lime than from 

 equivalent amounts of CaO as ground limestone. 



Let us now turn from these results where the limestone had been 

 in contact with the soil for but a relatively short time and con- 

 sider the case of the Pennsylvania Station plats at the end of 

 thirty years of liming. In the Pennsylvania experiments two tons 

 of almost pure lime have been applied each year to one of the 4 

 tiers, the one growing corn, while two tons of ground limestone 

 of corresponding purity have been? applied each year to the tiers 

 growing corn and wheat. Each tier then received 2 tons of burnt 

 lime every fourth year, and two tons of ground limestone every 

 second year. Thus, all the burnt lime of each application has 

 been exposed upon one series of plats, while the ground limestone 

 has been subjected to leaching from twice the soil area. That is, 

 in- each rotation of com, oats, wheat and grass, the entire amount 

 of burnt lime was applied to the com, while oae half of the ground 

 limestone was applied to each the corn and wheat. The results 

 obtained after thirty years of liming are given in Table V which 

 show in a very convincing manner the fact that, in spite of the 

 increased solubility of burnt lime after carbonation, we do not 

 lose proportionally more of the base when it is applied in the 

 oxid form than when applied as limestone. Furthermore, in 

 practice different conditions would exist. Practically all of the 



