758 



SCIENCE. 



[N.S. Vol. XVIll. Xo. 407 



pi-eted physical analysis is ordiliarily given. 

 Even when the mineral composition of the 

 soil is obvious, these meaningless local names 

 are retained as against preexisting local or 

 descriptive designations. Thus we have, e. g., 

 a ' Fresno sand ' appearing also in the report 

 on Orange and Monterey Counties, California 

 — localities hundreds of miles apart. To the 

 uninitiated only the physical analysis is offered 

 as a mark of their identity by the trained ob- 

 server. It seems a pity that that training 

 should not have extended to calling that ma- 

 terial a granitic sand, which would have ren- 

 dered the designation intelligible all over the 

 world, at the same time conveying important 

 practical information in view of the well- 

 known cultural characteristics and value of 

 granitic soils. It is given out that these 

 studies will be made later in the laboratory. 

 But it may be seriously questioned whether it 

 would not be better to cover less ground more 

 thoroughly, and be content with less extended 

 and hasty mapping. This superficial method 

 of work naturally excites criticism, not only 

 at home, but also abroad.* 



Until some better proof of identity is shown 

 we can not accept Whitney's conclusions based 

 on the similarity of the soil solution with 

 widely varying production on ' the same soil ' ; 

 and his entire argument suffers seriously from 

 the absence of any convincing ' proof that 

 ' rich ' soils do not supply plant food, even in 

 aqueous solution, more rapidly than does 

 ' poor ' land. 



But is the aqueous solution the only source 

 of supply? Whitney rejects in toto the idea 

 that anything but the carbonic acid secreted 

 by the roots aids the solution of plant food; 

 but his method of analysis practically ignores 

 even this solvent, the use of which was sug- 

 gested and actually carried out by David Dale 

 Owen, and tried by myself, in the early fifties. 

 I found it unsatisfactory and abandoned it; 

 but it would seem to have been incumbent 

 upon Whitney and his coworkers to introduce 

 this ineviteible agency into their soil extrac- 

 tions, if it was intended to represent natural 



* liiedcrmuniis Ceiitialblatt, February, 1903, p. 



conditions. This is a fundamental, not to say 

 fatal, defect. 



But there is still a wide difference of opinion 

 in this matter of the acid root secretions, and 

 the investigators quoted by Whitney have by 

 no means settled the matter. Among others, 

 Kossowitch,* when observing the fact that 

 calcic bicarbonate leached from his vegetation 

 pots, failed to establish the absence of other 

 organic acids from the solution. The old 

 etching experiments have not, to my mind, 

 lost their force ; and in my experience I find it 

 difficult to overcome the evidence of litmus 

 paper reproducing a faithful image of citrus 

 roots (in the soil) filled with a .83 per cent, 

 solution of citric acid.f If the paper can 

 take up the acid from the root surface, surely 

 the much stronger capillary action of the soil 

 can do so, according to Cameron's experiment 

 quoted on page 54.:]: But if so, Whitney's en- 

 tire argument based on watery soil soltitions 

 falls to the ground. 



Not the least remarkable part of the bul- 

 letin is that in which Whitney discusses the 

 use and action of fertilizers. He does admit 

 that ' there is no question that in certain cases, 

 and in many cases, the application of com- 

 mercial fertilizers is beneficial to the crop.' 

 But he calmly brushes aside, as so many cob- 

 webs, the enormously cumulative evidence of 

 all the practical experience of three quarters 

 of a century in the use of commercial fertil- 

 izers, as well as the carefully guarded culture 

 experiments made during that time by numer- 

 ous scientific workers ; and announces the 

 truism that climatic and seasonal conditions 

 may neutralize the beneficial effects of any and 

 all fertilizers used. This has been long and 

 often said, experienced and foreseen ; every one 



••' ■ Ann. de U Sc. Agron.,' 2 ser., 1, 220, 1903. 



t Report Calif. Expt. Sta. for 1S95-C and 

 189G-7, p. ISl. 



t " ^\'hen a porous cell having deposited in it 

 a semipermeable membrane through which water 

 can pass freely, but through which salts and cer- 

 tain organic substances like sugar can not pass 

 readily, is buried in a soil short of saturation, 

 but yet in fair condition for plant growth, the 

 soil will draw water from the cell against a calcu- 

 lated osmotic pressure in the cell of 30 atmos- 

 pheres, or. about 500 pounds per square inch." 



