SOILS — FEETILIZERS. 617 



Ing and other modern methods a payable crop is obtained on a lower rainfall 

 than is the case in any other part of the world. (6) The slight ground frosts 

 which often occur in the winter nights appear to simulate the growth of the 

 cereals when followed by 10 hours of bright sunshine. (7) The cliief problem 

 which has now to be solved is to devise methods by which large numbers of 

 sheep and cattle can be profitably kept on the wheat farms in the 10-in. rain- 

 fall regions. (8) Lands originally covered with scrub and producing very 

 little grass have been proved to be very suitable for wheat. With the gradual 

 advances in the numbers of stock kept on these farms permanent agricultural 

 settlement is likely to extend well beyond the 10-in. line of rainfall." 



The influence of weather conditions upon the amounts of nitric acid and 

 of nitrous acid in the rainfall near Melbourne, Australia, V. G. Anderson 

 (Rpt. Brit. Assoc. Adv. Set., 1914, pp. 338, 339). — A previous article based upon 

 the observations loere briefly reported has already been noted (E. S. R., 31, 

 p. 812). 



The influence of weather conditions upon the amounts of nitric acid and 

 of nitrous acid in the rainfall at and near Melbourne, Australia, V. G. 

 Anderson (Quart. Jour. Roy. Met. Soc. [London'], 41 (1915), No. 174, PP- 

 99-122, figs. 11). — The amounts of nitrous and nitric acids were determined in 

 the rainfall at the center of Melbourne and at the suburb of Canterbury 

 six miles distant during 16 months beginning Noveml)er 1, 1912, as previously 

 noted (E. S. R., 31, p. 812). The nitrous acid was determined by a modifica- 

 tion of the method of Griess and the nitric acid by the salicylic acid method 

 of Caron and Raquet (E. S. R., 25, p. 613). 



Correlation of the data with the meteorological elements of Melbourne and 

 with the daily isobaric charts of Australia showed " the existence of a relation 

 between weather conditions and the amounts of the nitrogen acids in the 

 rainfall. ... A relation between atmospheric temperature and the ratio of 

 nitric nitrogen to nitrous nitrogen was observed, and according to the results 

 it seems probable that, in rain water, nitric and nitrous acids are formed 

 in equal molecular proportions, and that the effect of variations in temperature 

 is to change the velocity of transformation of nitrous acid into nitric acid, 

 resulting in a high ratio in summer and a ratio approaching unity in winter. 

 . . . For a given type of weather, and in samples of rain water collected dur- 

 ing 24 hours (a) the concentration of oxidized nitrogen varies inversely as 

 the rainfall, and therefore (b) the product of the concentration of oxidized 

 nitrogen and the rainfall is constant. . . . Amounts (pounds per 1,000 acres) 

 of oxidized nitrogen per day varying from 1.5 in the case of certain antarctic 

 storms to 35 in the case of intense tropical storms " are reported. 



In the discussion following the paper especial emphasis was laid on the 

 importance of determining the amounts of ammonia as well as of nitrous and 

 nitric acids in, the rainfall. 



SOILS— FERTILIZERS. 



Thirty-nine experiments in soils, C. L. Quear (Muncie, Ind.: Author, 1915, 

 pp. 90, figs. 15). — In this publication 39 soil experiments and 13 supplementary 

 experiments are outlined for the use of beginners in the study of agriculture. 



Surface formations and agricultural conditions of northwestern Minne 

 seta, F. Leverett and U. G. Pukssell (Univ. Minn., Geoh Survey B 

 (1915), pp. Yl+18, pis. 8, figs, i^).— This report describes the topogra 

 geology, and climate of northwest jMinnesota, and deals at length with the soil 

 and agricultural conditions and land classification by counties. 



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