May 12, 1911] 



SCIENCE 



741 



have come from the mistaken notion that an 

 anticyclone brought down air from the upper 

 strata, and therefore ought to be cold. The 

 descending air does occur, but the tempera- 

 ture during an anticyclone a few hundred feet 

 high is unduly warm." In the April number 

 Dr. J. Hann points out the fact that it is not 

 the absolute height of the barometer that is 

 determinative in locating anticyclones, but 

 rather the relative height of the barometer 

 compared with that of the surrounding dis- 

 tricts. He maintains that the center of an 

 anticyclonic area is cold in winter, " a focus 

 of cold " — an opinion supported by the inves- 

 tigations of Hildebrandsson on temperatures 

 in cyclones and anticyclones. " The cold 

 arises in winter in anticyclonic regions as a 

 result of radiation favored, in a high degree, 

 by the clear skies and the dry air of the anti- 

 cyclonic center. One can say definitely that 

 the cooling of the earth in the winter half- 

 year is accomplished mainly in the anti- 

 cyclonic areas of the land surface. ISTocturnal 

 radiation is very intense in the dry air, espe- 

 cially when the surface of the ground is cov- 

 ered with snow." The extremes of the winter 

 months in central Europe show no constant 

 relation to the variations of pressure in cen- 

 tral Europe itself, as the "focus of cold" is 

 usually at the center of a persistent conti- 

 nental anticyclone to the northeast. Only in 

 exceptional cases is central Europe itself the 

 seat of this center, and when it is, abnormally 

 cold weather is experienced. As the British 

 Isles usually remain on the western side of 

 the European anticyclone, and thus have 

 southerly and southeasterly winds with high 

 barometer, it follows that high temperatures 

 quite often accompany the high barometer. 

 At the same time, however, it is cold on the 

 continent in the center of the European anti- 

 cyclone. 



Andrew H. Palmer 

 Blue HttL Observatory, 

 April 25, 1911 



TKE SOIL, A LIVING THING 

 For many years the fertility of the soil was 

 sought in the chemical substances which analy- 



sis proved to be essential to plants and which 

 could be exhausted from the soil by the con- 

 tinual growth of a single crop upon it. To 

 restore the fertility of the soil, it was neces- 

 sary only to restore the ingredients necessary 

 to keep a plant in a productive condition. Fer- 

 tilizers were applied which were known to 

 contain the most important materials of plant 

 food and in an available form. Even to-day, 

 there are opposing camps of plant physiolo- 

 gists. One set holds to the principles, first 

 clearly enunciated by Liebig, that the chemi- 

 cal condition of the soil is the most influential 

 factor in the productivity of the garden, or 

 farm. The other group consider that the 

 physical condition of the soil influences the 

 tilth. This school teaches that all agricultural 

 soils contain sufiicient quantities of the essen- 

 tial mineral plant foods for many years to 

 come. Eeeently a more advanced position has 

 been taken by some students of the soil, when 

 they claim that the loss of fertility of many 

 long cropped soils is due to the accumulation 

 of toxic bodies, the accumulated excreta of 

 plants that may have been grown without 

 proper rotation. The true theory of soil 

 fertility will probably be found to be one 

 which will combine all of these theories with 

 another one, which I believe must also be con- 

 sidered in reaching a satisfactory conclusion 

 as to the relation existing between crops and 

 the soil in which they grow. 



The theory is one which considers that the 

 soil is a living thing apart from its chemical 

 or physical structure, that in the reaction be- 

 tween the living soil and the growing plant 

 is the true explanation of soil fertility. A 

 fertile soil is a live one. An infertile soil 

 is a dead one. Contrast the soil which is filled 

 with organic matter (humus) and in which 

 numberless fungous, bacterial and protozoan 

 organisms are at work with a mass of clay or 

 sand without such organic material and asso- 

 ciated living organisms. The one soil is 

 fertile, because the organisms in the soil 

 react favorably upon each other, the other soil 

 is infertile, because the organisms present in 

 this soil are antagonistic. Recent investiga- 



