WATER SOILS. 393 



carbouate of lime in tbo soil coutaiumg the 5 per cout of ranguesiuin sulphate. The 

 reaction of the lime iu rendering- tlie maguesiuni s;iit msolnble would be quicker, 

 and better results were t .erefore exiiected tbau in the foregoing series. This pre- 

 diction proved correct Though germination was somewhat retarded, a greater 

 percentage of ))lants grew and attained a larger and healthier growth than in the 

 soil containing the antidote, carbouate of lime. It was evident that the lime proved 

 the more efficacious of tlie two.'' 



On the action of common salt, phosphates, and nitrate of soda 

 in rendering soluble the potash of the soil, N. Passerini {Atti. R. 

 Acrad. Econonilco-iKjrdrla Fircnze., 7:2 {1891), pp. 15-25). — The investi- 

 gations of Deherain and of Cossa on the effect of j?ypsuni on the sola- 

 bility of potash in the soil led the author to study the effects of the 

 above-named fertdizers on tlie solubility of iiotash, lime, and magnesia. 

 December 17, 1892, 500 gin. lots of earth very rich m potash (1.23 per 

 cent K2O) were placed in glass vessels washed with boiling hydro- 

 chloric acid; with this soil there had been previously mixed 20 gm. of 

 either common salt, monocalcic phosphate, tricalcic phosphate, or 

 nitrate of soda. In one series of vessels the earth was kept moist, in 

 another dry, and checks were emiiloyed. Dust, but not air, was 

 excluded. Analyses of the mixtures were made from July to Septem- 

 ber, 1893. The solubility in boiling water was determined, using 1 liter 

 of water iu washing oOO gm. of soil. 



When common salt was added to the soil each kilogram of the latter 

 when kept moist contained 0.1831 gm. of soluble potash in excess of 

 that of the earth without salt, and an excess of 0.0725 gm. when the 

 treated soil was kept dry. Thus in 8,000,000 kg., which the author 

 estimates as the average weight of the active stratum of a cnltivated 

 soil of 1 hectare, he states that there had been made soluble by means 

 of common salt in a humid soil 1,105 kg. of potash per hectare, in a 

 dry soil 580 kg. of potash. 



Attention is called to the fact that the proportion of fertilizer to soil, 

 1 to 25, is much greater than is possible in field i^ractice; hence with 

 smaller amounts of fertilizer we should expect less activity in convert- 

 ing insoluble potash into soluble forms. 



Common salt also rendered soluble a large quantity of lime and mag- 

 nesia, although the solubility of these substances was not increased 

 by keeping the soil humid as compared with keeping it dry. The 

 author states that common salt could not be expected to jiroduce good 

 results on soils poor in potash. The injurious elfects sometimes noticed, 

 he attributes to its corrosive influence on plant roots, or to its action 

 in suspending nitrification, as, according to Deherain, 0.4 per cent of 

 salt is sufficient to prevent this process. 



Only the purest monocalcic phosphate was used in these experi- 

 ments. In a moist soil it mado soluble 0.0125 gm., and in a dry soil 

 0.0099 gm. of potash in every kilogram of soil ; or in every 8,000,000 

 kg., 100 kg. and 79.2 kg., respectively. 



When tricalcic phosphate was used with dry earth the solubility of 



