G28 



SCIENCE. 



[N. S. Vol. XIX. No. 485. 



is applied to this soil, which already contains 

 such an abundance of nitrogen and phos- 

 phorus, the yield should certainly rise to 60 

 bushels or more. Of course, there are reasons 

 why the plots yielding 36 to 40 bushels did not 

 yield 60 bushels instead of only 36 or 40. 

 These reasons are fully explained in Illinois 

 Bulletin No. 93, ' Soil Treatment for Peaty 

 Swamp Lands.' Soils may all look alike to 

 the theoretical chemist, but any one who is 

 familiar with agricultural science and practise 

 recognizes that there are differences in soils. 

 Indeed, it seems pertinent to state that these 

 differences were fully understood by the prac- 

 tical farmers who watched the experiments, 

 and who are now using carloads of potassium 

 salts with very great profit on these soils. 

 In 1903 five plots not treated with potassium 

 yielded 15, 7, 4, 5 and 4 bushels of corn, re- 

 spectively; while five other plots, with potas- 

 sium applied, yielded Y3, 71, 73, 67 and 70 

 bushels. 



All agricultural chemists will agree with 

 Doctor Wiley's statement wherein he says : 

 " When a man sends to me a specimen of a 

 given soil and writes, ' Please analyze this 

 soil and tell me what crops I can grow on it,' 

 I send him word, ' Ask your soil itself what 

 you can grow on it; in that way, asking your 

 question directly of the soil, you can get your 

 answer, and in no other.' " 



Chemists recognize that soils have physical 

 as well as chemical properties. On the other 

 hand, no agricultural chemist of standing will 

 agree with the statement of Whitney and 

 Cameron, ' that a chemical analysis of a soil, 

 even by these extremely delicate and sensitive 

 methods, will in itself give no indication of 

 the fertility of this soil,' understanding that 

 the use of the word even is intended to con- 

 vey the meaning that no other known methods 

 need be thought of if these fail. Further- 

 more, it is certainly pertinent to the discus- 

 sion to state here that Professor King, a 

 recognized authority on soils and a careful 

 and exact investigator, found that the chem- 

 ical analysis of soils, even hy these methods, 

 furnishes much information regarding the 

 fertility of soils. According to notes which I 

 made from Professor King's address on the 



differences between some southern and north- 

 ern soils in the United States, read before the 

 Association of American Agricultural Col- 

 leges and Experiment Stations, he found that 

 the northern soils contained 2.39 times as 

 much water-soluble plant food as the" south- 

 ern soils and he also found that the yields of 

 crops produced on the northern soils were 

 2.47 times the yields produced on the southern 

 soils. This is in direct contradiction to the 

 conclusions drawn by Whitney and Cameron 

 from the very miscellaneous and discordant 

 data reported in Bulletin 22. The investiga- 

 tion by Professor King and his assistants is 

 evidently the most systematic accurate and 

 valuable work which has yet been done by the 

 Bureau of Soils; and it is certainly to be 

 hoped that these investigations will soon be 

 published in full, even though, being con- 

 nected with the Bureau of Soils, Professor 

 King can not ' anticipate the publication of 

 the proceedings ' of the Washington meeting. 



The only just criticism of Circular 72 which 

 Doctor Cameron makes in his ten-column 

 article in Science is in regard to the state- 

 ment concerning the methods employed by the 

 Bureau of Chemistry in analyzing the Eoth- 

 amsted soils. These- statements were based 

 on notes taken from the public discussion by 

 the author of the Journal article* at the 

 Washington meeting. Either Mr. Moore 

 misspoke himself in saying ' fifteen hours' ex- 

 traction ' and ' gravimetric method,' or he 

 said 'five hours' extraction' and 'volumetric 

 method ' and I misunderstood him ; and I 

 humbly accept Doctor Cameron's scathing re- 

 buke for not having looked it up in the orig- 

 inal paper. Cameron also insists upon hav- 

 ing mention made of the twenty minutes 

 allowed for settling in his water extraction. 



The corrections suggested by Doctor Cam- 

 eron being accepted the obnoxious statement 

 regarding the work from the two bureaus on 

 the same soil samples would then read as 

 follows : 



It will be observed that tlie Bureau of Soils by 

 twenty-three minutes' extraction with distilled 

 water at room temperature reports from two to 

 thirteen times as much soluble phosphorus from 



* Journal American Chemical Society, 24, 94 

 (190.3). 



