422 BXPEEIMENT STATION EECOED. 



nate the errors in determining the structure and density of a soil which are due 

 to loss of part of the sample, disturbance of the structure, adhesion to the 

 sampler, and errors in determining the depth of sample. 



As a means of preparing sections of soils for the study of their structure, the 

 samples were immersed in a melted 3 : 1 mixture of paraffin and stearin, which 

 was then allowed to harden and thus preserve the original structure intact. 

 Studies of sections of a plowed and scarified moist loam by this method showed 

 the scarified soil to be in much the better physical condition for plant growth. « 



The study of clay, A. MtJNTz and H. Gaudechon {Gompt. Rend. Acad. Sci. 

 [Paris], 157 {1913), No. 21, pp. 968-91 It, fig. 1; ahs. in Rev. Sci. [Paris'], 51 

 (1913), II, No. 23, pp. 731, 732; Jour. Chem. Soc. [London], 106 (1914), No. 615, 

 I, pp. 127, 128). — For determining the fineness of clay the authors studied the 

 division of the clay particles in a given time at different heights in a homo- 

 geneous suspension. For producing sedimentation they employed gravity and 

 the combined action of gravity and an electrical field. By the use of gravity 

 the larger particles settled more rapidly while by the use of the electrical field 

 the finer particles settled more rapidly. 



It is considered possible by these methods to establi;^h a purely artificial 

 classification of clays, indicating for each the quantities deposited from the 

 suspension during an arbitrarily chosen period of time. 



Estimation of the lime requirement of soils, J. A. Bizzell and T. L. Lyon 

 (Jour. Indus, and Engirt. Chem., 5 (1913), No. 12, pp. 1011, 1012).— A modifica- 

 tion of the barium hydroxid and ammonium chlorid method proposed by Albert ' 

 is described, and tests of the method in comparison with that of Veitch are 

 reported. The proposed method is thought to be more rapid and as accurate 

 as that of Veitch. 



On the circulation of sulphur and of chlorin on the earth, and on the 

 importance of this process in the evolution of soils and in the plant 

 world, P. S. KossovicH (Zliur. Opytn. Agron. (Russ. Jour. Expt. Landw.), 

 H (1913), No. 3, pp. 181-228; ahs. in Internat. Inst. Agr. [Rome], Mo. Bui. 

 Agr. Intel, and Plant Diseases, 4 (1913), No. 10, pp. 1522-1526) .—The following 

 topics are discussed: Chlorin and sulphur in rocks and soils, atmospheric pre- 

 cipitation, and subsoil waters ; the role of chlorin and sulphur from atmospheric 

 precipitation in soil evolution ; and chlorin and sulphur contents and require- 

 ments of plants. 



Rocks were found to contain only small quantities of chlorin and sulphur, and 

 soils only small amounts of slightly soluble sulphur which decreased with the 

 depth. Soils rich in humus contained as high as 0.1 per cent of sulphur. 



Data collected in European Russia and available data for other countries 

 indicate that the chlorin and sulphur contents of the several atmospheric pre- 

 cipitations vary widely, the chlorin from 0.4 to 71.9 parts per million and the 

 sulphur from 0.28 to 90.2 parts per million, while the yearly averages vary 

 within much narrower limits. The quantities of these elements falling with 

 the precipitation per acre per year varied considerably in the localities exam- 

 ined, the chlorin in most territories being between 8.92 and 22.30 lbs. per acre, 

 and the sulphur between 8.92 lbs. in the country and 72 lbs. per acre in the 

 neighborhood of towns and industrial works, where the greatest portion falls 

 in winter. The chlorin content of the atmospheric precipitation increased as 

 the locality approached the seas and oceans or bordered on salt lands, and 

 slight precipitations generally contained more chlorin than the heavier ones. 



Theoretical considerations led to the conclusion that soil and subsoil water 

 contains more chlorin and sulphur than atmospheric precipitation due to the 

 evaporation of the latter, and that the relative chlorin and sulphur contents 



