SOILS I'Kin II.IZKKS. ■ filO 



tlio soil and siiltsoil, or peculiar inclt'orolofjii-al coiKlitions. the subsoil docs not 

 lanouie moistened down to the water level. A ]»art of the ]»lant fo<Ml taken u]) 

 \>y the trees is returned to the surface of the soil by the decayed leaves. In the 

 absence of snflicient moisture to thoroughly wet the subsoil, however, the leaf 

 ash constituents are uot washed very deep; hence an annually increasinj; ex- 

 haustion of certain soil layers leadinir to the death of new forest jjlantinjrs when 

 the roots reach these layers. 



Theoretical considerations regarding- factors influencing certain of the 

 so-called physical properties of soil, P. KiiHi:M5i;R(i (Mitt. Lnndir. Just, liits- 

 luii, J, (JUGS), .Vo. ,1 1)11. .'i.',5-'i'.).{: ahs. in Chcm. Znithl., IDOS. J. \(,. „>«. /*. ^HH : 

 i'luin. Ztf/.. 32 (t!)OS), Xo. 7.i. Rcpcrt., i>. .J6'.?). — This article discusses at con- 

 siderable length the theory of colloids, nature of colloids in cultivated soils, and 

 importance of colloids in relation to the physical, chemical, arid biological jMop- 

 iMties and ]»rocesses of soils. 



On physical properties of soils, II. Kodkwald ( Fiihlini/'s Luiiilir. Ztt/.. .',7 

 ( I'.iOS). .Yo. f.{. mi. .^.7.7-J.<(S'). — A review of the above article. 



Note on a flowing (melting-) soil, A. (;i!f:(ion?K {But. Inst. ('hint. <t liact. 

 Gcmhlou.F, WOS, \o. 7.7. ///>. Sd-DS). — A study of the structure and physical i)rop- 

 erties of a line-grained soil which easily breaks down and foi-nis a li(nii<l mass 

 when wet is retiorted. 



The lines of flow of water in saturated soils, L. F. IIichardson (Sci. I' roc. 

 Hull. Dultlin Sue. n. scr.. II (I90S). .Vo. .^7. /</*. JU.j-.iKi. fif/s. 7).— This article 

 exj)lains '"a simple method for determining the relation i)etween the distance 

 apart of ditches and the heiglit to which the saturating water will rise with ;i 

 given rainfall, special reference being made to the draining of i)eat-mosses."' 

 The fornitilas and diagrams deduced for the jturpose are based upon I'.ous- 

 siiiesii's difterential equations for the percolation of water in a nonexpanding, 

 liorous soil, which in turn ai-e found(Ml on the supposition that the general 

 \elocity of the water is proportional to the i)ressure gradient. 



The relation of soils to water with special reference to the formation of 

 ground water, (\ 'SIvm.vk (dsniltx. Infiin.. .il (J!)OS), Xo. Id, pp, 2'il-.i')l, 

 fiflK. .'/). — This is a discussion of the balance of evajioration. ]>recipitation. and 

 (li-ainage. and the relation of soils to liygrosco|>ic moisture, as brought out by 

 the work of various investigators. 



Soil wastage, T. ('. C'h.vmi!i;ki.i.n' {Pop. Sri. Mo., 7.? itlXJS). Xo. I. pji. 7- 

 /-). — The causes, extent, and practical means of jjrevention of soil exhaustion 

 liy erosion and leaching are discussed in this article, and it is shown that the 

 solution of the problem lies in due control of the water which falls on the sur- 

 face and that "all the rainfall during the growing season, and much or all of 

 that which can be carried over from the nongrowing sea.sons" can be used 

 with profit by tlie adoption of suitable methods <if tillage and cropiting. 



Soil temperature investigations, A. IIkckkk U'iililintj'.s Landw. Ztf/.. .77 

 ( l!)OS). Xo. I.i, pp. '/.7.S-J7/ t.^Kxtensive series of observations are reported 

 which lead to the conclusion that certain feitilizers. particularly well-rotted 

 manure, lime, kainit. etc., exert a marked inllnen<-(> on the temperature condi- 

 tions of the surface soil. This action is considered tn be indirect and due to the 

 influence of these sulistances on the iil)ysi<-al ja-nperties md iirocesses of the 

 soil. 



Manure, lime, and magnesia m;ike the .soil jiorous and thus re<luce conductive 

 power for heat. Kainit and nitrate of soda in large amounts make the .soil 

 more compact and thus increase conductive ]iower. I'nder the lirsl coiidifiou 

 v.iriations in lemper.-iture are greater than under the .><4'coiid. i. e.. there :ire 

 higher temperatures during tin- day ami lower diirimr the niglil. 



