NOVEMBEB 30, 1906,] 



SCIENCE. 



683 



California, showing the great differences in 

 depth of the soil proper, thus giving a basis 

 for understanding the possibility of deep 

 humijS-cation, nitrification, root feeding and 

 high duty of soil moisture which distinguish 

 arid from humid soils, making them relatively 

 more productive and more enduring. Chap- 

 ters XI., XII. and XIII., in all 78 pages, are 

 devoted to the water of soils, placing the 

 greatest emphasis upon the problems of semi- 

 arid and arid regions, while the remaining 

 three chapters of this part deal with the ab- 

 sorption of solids from solution, and gases, 

 the color of soils and climate. 



Part III. is an extremely cogent and clear 

 presentation of the author's and others' ob- 

 servations and conclusions regarding the 

 legitimate functions, possibilities and utilities 

 of chemico-physical investigations of soils in 

 regard to crop production. A careful study 

 of these chapters will be found a speedy and 

 complete antidote for that miasma which rose 

 up out of Maryland, infected the national 

 capital and, on the wings of publicity, is de- 

 veloping ' toxic ' symptoms at widely separated 

 centers. The first chapter of this part, among 

 other matters, gives a brief historical review 

 of soil investigations; calls attention to ad- 

 vantages for soil study offered by virgin lands ; 

 points out the physical and chemical condi- 

 tions of plant growth; discusses the solvent 

 action of water upon soils; the ascertainment 

 of immediate plant food requirements and 

 chemical tests of immediate productiveness. 

 The second chapter treats of the analysis of 

 virgin soils by extraction with strong acids, 

 the limits of adequacy of the several plant- 

 foods in virgin soils and the influence of lime 

 upon soil fertility, wherein it is held that 

 ' a lime country is a rich country.' The next 

 two chapters are given over to a very fruitful 

 comparison of the soils of arid and humid 

 regions, in which tropical soils, so far as data 

 are available, come in for their share of con- 

 sideration. The last two chapters of Part III., 

 on alkali soils and the utilization and reclama- 

 tion of alkali lands, all very comprehensive 

 and practical discussion of those problems 

 which must prove very helpful to agents of 

 the reclamation service and to actual and in- 



tending settlers on those lands, 62 pages being 

 very wisely given over to these important 

 matters. 



Soils and Native Vegetation is the title of 

 Part IV. Quoting, but not consecutively, 

 the author says : 



In newly settled countries, and still more in 

 those yet to be settled, the questions of the im- 

 mediate productive capacity, and the future dura- 

 bility of the virgin land are among the burning 

 ones since they determine the future of thousands 

 for weal or woe. This need has long ago led to 

 approximate estimates, made on the part of the 

 settler, by the observations of the native growth, 

 especially the tree, growth. * * * Thus in the 

 long-leaf pine uplands of the Cotton States, the 

 scattered settlements have fully demonstrated 

 that after two or three years cropping with corn, 

 ranging from as much as twenty-five bushels per 

 acre the first year to ten and less the third, fertil- 

 ization is absolutely necessary to farther paying 

 cultivation. * * * Corresponding estimates based 

 upon the tree growth and in part also upon minor 

 vegetation, are current in the richer lands also. 

 The ' black-oak and hickory uplands,' the ' post- 

 oak flats,' ' hickory bottoms,' ' gum bottoms,' 

 ' hackberry hammocks,' ' post-oak prairie,' * red- 

 cedar prairie ' and scores of other similar designa- 

 tions, possess a very definite meaning in the minds 

 of farmers and are constantly used as a trust- 

 worthy basis for bargain and sale, and for crop 

 estimates. * * * Since the native vegetation 

 normally represents the results of secular or even 

 millennial adaptation of plants to climatic and 

 soil conditions, this use of the native flora seems 

 eminently rational. * * * It seems singular 

 that such well and widely understood designa- 

 tions and important distinctions should not long 

 ago have been made the subject of careful investi- 

 gation and precise definition by agricultural in- 

 vestigators. For apart from their practical im- 

 portance as guides to the purchaser of land, or 

 settler, this correlation of land values and natural 

 vegetation is of the utmost interest in offering an 

 opportunity for researches on the factors which 

 determine the choice of these several trees and 

 their corresponding shrubby and herbaceous 

 groAvths. * * * Only very fragmentary and 

 casual observations in this line are on record thus 

 far. * * * Yet, to ascertain by the physical 

 and chemical examination of soils what are deter- 

 mining factors of certain natural vegetative pref- 

 erences, which are invariably followed by certain 

 agricultural results, should not be an unsolved 



