774 



SCIENCE 



[N. S. Vol. XXX. No. 778 



influence of the legume on nitrification is in- 

 dicated by the following figures: 



These plats had all been limed to their indi- 

 cated requirements. The nitrification tests 

 were made according to the following method : 

 100 grams of the moist soil were placed in a 

 250-c.c. bottle. To this was added 500 milli- 

 grams of ammonium sulfate and sufficient 

 water to bring the soil to a moisture content 

 of 25 per cent, calculated on the basis of dry 

 soil. The bottle after insertion of a tight 

 cotton plug in the mouth was placed in the 

 incubator and kept at a temperature of 30° 0. 

 for the time indicated. Once each week water 

 was added to replace that lost by evaporation. 

 Nitrates were determined according to the 

 method described in Bulletin 31, Bureau of 

 Soils, U. S. Department of Agriculture. 



That the availability of the soil nitrogen is 

 increased by the growth of alfalfa is also indi- 

 cated by analyses of timothy when grown 

 alone and when growing as a mixture of 

 timothy and alfalfa. The pure timothy, en- 

 tirely isolated from other plants, contained a 

 higher percentage of nitrogen when grown 

 with alfalfa than when grown alone. This 

 was true on both the limed and the unlimed 

 soil. Alfalfa, and possibly other legumes, are 

 thus of immediate benefit to the soil and to 

 the crop growing with them. 



The fact that Kellerman and Eobinson were 

 dealing with soils growing leguminous crops 

 while Stevens and Withers tested soils without 

 regard to the crop grown upon them may, in 

 a measure, account for the more pronounced 

 nitrification found by the former investiga- 

 tors. The writers must state, however, that 

 they have not found any natural field soils in 

 which nitrification does not take place. 



Analyses of Erigeron annuus growing on 



limed and unlimed soil showed, in nine out of 

 ten cases, a higher percentage of nitrogen in 

 the plants growing on limed soil. The soil 

 was deficient in lime. This is mentioned as 

 another indication that nitrification, or at 

 least the availability of soil nitrogen, is in- 

 creased by the use of lime on soils in which 

 they are deficient. 



Our conclusion is that the presence of a 

 certain degree of basicity in the soil, and pos- 

 sibly the growth of certain nodule-bearing 

 legumes, are each favorable to nitrification in 

 the soil. These and other conditions may 

 account for very considerable differences in 

 nitrification tests in different soils. 



T. Lyttleton Lyon 

 Jas. a. Bizzell 



Cornell Univeesitt 



THE NATIONAL AGADEBIT OF SCIENCES 

 The autumn meeting of the academy was held 

 at Princeton on November 16, 17 and 18. The 

 general program was as follows: 



TUESDAY, NOVEMBEE 16 



10:00 A.M. Meeting of Council. 

 11:00 Scientific Session. 



12:45 P.M. Address of Welcome by President 

 Wilson. 



1:15 Luncheon. 



2:15-3:15 Scientific Session. 



3:15 Lecture on the Investigations of 



Joseph Henry, illustrated by Pro- 

 fessor Henry's own apparatus, by 

 Professor W. F. Magie. 



4 : 30 Reception of the Academy and guests 



by Mr. and Mrs. A. D. Russell. 



8:00 Dinner to the Academy by the Presi- 



dent and Faculty of Princeton 

 University. 



WEDNESDAY, NOVEMBER 17 



10:00 A.M. Meeting of Council. 

 11:00 Business Session. 



1:00 P.M. Luncheon. 

 2:30 Scientific Session. 



3:00-5:00 Conversazione: An exhibition illus- 

 trating recent scientific investiga- 

 tions, open to the public, in the 

 Museum, Guyot Hall. 

 8 : 00 Concert of the Philadelphia Orchestra. 



