SOILS PERTILIZEKS. 527 



of wliicb muiiber 127, or 45 per cent, were found to be receiving sewage pollu- 

 tion, while iu 47 cases, or 17 \)er cent, tbe quality of the water was not satis- 

 factory. Out of 76 supplies wbere tbe waters were sui)posed to be tbe origin 

 of typboid fever, 58 per cent of tbe samples sbowed large amounts of sewage 

 pollution, wbile tbe quality of tbe water in 11 cases, or 14 per cent, was unsatis- 

 factory. . . . 



" Tbe fact tbat so many wells are receiving sewage pollution bas led to an 

 investigation of tbe scbool supplies in the State, and the results obtained thus 

 far indicate tbat a great many changes are needed. Comparatively few schools 

 in the State have their own water supply, the water being usually obtained 

 from tbe nearest private well, and these are in a great many cases seriously 

 polluted. Of 202 supplies examined thus far, 42 per cent were found to be 

 receiving sewage pollution and 17 ijer cent were dirty or unsatisfactory. . , . 



" No investigation of tbe wells on dairy farms bas as yet been made, but the 

 number of typboid fever epidemics which have occurred along tbe routes of 

 dairymen in various parts of the State would seem to show tbat such an investi- 

 gation would be of considerable value iu helping to eliminate tbe possibility of 

 such epidemics." 



SOILS— FERTILIZERS. 



On the lime requirements of arable soils, M. Weibull (K. Landi'br. Akad. 

 Handl. och Tidskr., 48 {1909), No. 3, pp. 212-227, fig. i).— The paper describes 

 an investigation of the relation of the lime content, loss on ignition, and reac- 

 tion of South Swedish soils, conducted with a special view to devising a simple 

 method by which tbe need of lime may be determined in tbe case of arable 

 soils. 



Tbe results obtained lead the author to conclude that ordinary soils with 

 less than 3 to G per cent loss on ignition ("humus") and containing below 

 0.20 per cent assimilable lime (soluble in 10 per cent ammonium-chlorid solution 

 at boiling temperature) as a rule have acid reaction and a low power of nitri- 

 fication. Tbe soils low in lime tbat are not acid have a very low humus con- 

 tent. An alkaline reaction is found in common arable soils containing calcium 

 carbonate (if only a trace), and in soils containing no calcium cax-bonate but 

 more than 0.25 per cent assimilable lime: such soils have generally a high 

 power of nitrification. Exceptions with regard to reaction occur especially in 

 the case of soils with very high humus contents. Soils containing 0.20 to 0.25 

 per cent assimilable lime, on the other hand, have either neutral reaction or 

 are more indefinite with regard to reaction. 



If the results of tbe author are corroborated by further work with different 

 types of soils, tbe determination of tbe reaction of a soil (either by titration 

 with tenth-normal alkali or acid solution, using a lacmoid solution as an indi- 

 cator, or by tbe use of litmus paper) will furnish a simple and satisfactory 

 measure of tbe lime requirements of arable soils. Tbe method of sampling a 

 soil is, however, of inqiortance in this resi)ect, a number of sei)arate samples of 

 each field being generallj^ required, rather than a single sample or a composite 

 sample of a number of subsamples. 



Investig'ations of the influence of cultivation on the water content of 

 arable soils, T. Wesiermann (Tidsskr. Landbr. Plantcavl, 16 {1909), No. 1, 

 pp. 15-109, figs. 5). — The paper describes experiments with clayey and sandy 

 soils in zinc cylinders 125 cm. high and 79.8 cm. in diameter. These wei*e 

 placed in the gi-ound and i)rovided with a watering device. A full illustrated 

 description of llie cylinders is given in tbe paper. The permeability of tbe two 

 types of soils for water was carefully studied and the water contents of tbe soils 



