Apeil 17, 1908] 



SCIENCE 



631 



yield from the continuously unmanured wheat 

 plot has not been due to a loss of water 

 soluble material, or rather that there has been 

 no permanent disturbance of the solution 

 equilibrium and concentration," citing espe- 

 cially the bureau's analyses of soils from plots 

 3 and 11 of the Broadbalk field. Such data 

 are given in evidence, utterly ignoring the 

 detailed, full and careful data published from 

 the Eothamsted laboratories pointing strongly 

 to the very opposite conclusion, as may be 

 seen from the tables. Bulletin 26, Bureau of 

 Soils, pp. 23, 24, 80, 83. The detailed analyses 

 of the soil solutions leaving the Eothamsted 

 plots as drainage water show that that from 

 the plot continuously unfertilized are not only 

 the least concentrated of any in the whole 

 series of 16 plots, but that the total solids in 

 solution from this plot stand as 246.4 to 

 425.9 coming from plot 11, or as 100 to 173, 

 while the relative mean yields of wheat stand 

 as 100 to 215. Moreover, there is a remarkable 

 and clear relation between the yields of 

 nearly all of the plots of this series and the 

 concentration of the drainage water leaving 

 the respective plots, the yields generally in- 

 creasing with the soluble salt content of the 

 drainage water. Not only is this true for the 

 total soluble salt content, but the amount of 

 potash carried in the drainage water coming 

 from the plots to which potash fertilizers have 

 been continuously applied, when compared 

 with that from those to which none has been 

 given, stands in the ratio of 425 to 100, as 

 an average, and there is no individual 

 exception. 



Such, in brief, is the character of the data 

 spread out by Whitney and Cameron in Bul- 

 letin 22. Thus did they ignore pertinent, 

 undoubted facts collected by the bureau or 

 published elsewhere, tending to disprove their 

 views. Such is the almost utter lack of evi- 

 dence collected either by the bureau or by 

 others which may fairly be placed in support 

 of their m.ain contentions, and yet no work 

 has since been done, or at least published, 

 which can be placed in support of these views. 

 On the_ contrary, the energy of the bureau is 

 being expended in an effort to accumulate 

 data in support of the theory that poor and 



runout lands are so because of the accumula- 

 tion in them of imaginary toxic substances. 

 Bulletins 36 to 40 record their most strenu- 

 ous efforts along this line. 



Toxicity a^ a Factor in the Productive Capa- 

 city of Soils. 



In Bulletins 36 and 40 are given general 

 reviews of literature relating to this subject, 

 and in these and No. 28 the main body of 

 experimental data thought to support the 

 theory that soils are rendered unproductive by 

 poisonous excreta thrown off by the roots of 

 higher plants. However plausible and attract- 

 ive such a theory may appear, a review of the 

 data and discussions presented will convince 

 the unbiased student that little has yet been 

 done which may properly be considered other 

 than speculative contributions to the subject. 

 As pointed out, the main contentions of the 

 Bureau of Soils supposed to make the con- 

 sideration of the toxicity factor pertinent are 

 not supported by its own work or that of 

 others and are not true. It has made no 

 discovery, therefore, demanding such a factor; 

 but while this fact should be clearly recog- 

 nized, it may be well to retain the old theory 

 in the list of alternative working hypotheses, 

 although it must be conceded to offer less 

 of promise than many others or than it did 

 when originally proposed, for our present 

 knowledge makes it quite uncalled for in ex- 

 plaining observed relations. 



But were it true that toxic excreta do play 

 an important role in rendering soils unpro- 

 ductive, it must be admitted that nothing yet 

 has been published, either by the Bureau of 

 Soils or others, to which reference is made by 

 the bureau, which should in any sense be re- 

 garded as proof. Indeed, much of tlie bu- 

 reau's data can hardly rank as even sug- 

 gestive evidence regarding the existence of 

 such conditions in the field; because nearly 

 all of the work has been done with seedlings 

 placed under extremely cramped, abnormal 

 and unsanitary conditions, the plants fed 

 chiefly by the small amount of nutrients 

 stored in the seed, and the experiments termi- 

 nated after a few days or at most after two 

 or three weeks. In illustration, take the ex- 



