418 EXPERIMENT STATION RECOED. [Vol. 37 



The influence of inteu^e aud prolonged cannonading on rainfall. U. L>es- 

 LANDRES (Comijt. Rtud. Acad. Sci. [Paris], 164 (1917), No. 17. pp. 61S-615; 

 abs. in Rev. Sci. [Paris], 55 (1917), No. 9, p. 2S4).—lt is stated that artillery 

 discharges electrify and ionize the atmosphere to an extent which apparently 

 influences rainfall, although to a much less extent than the gi-eat atmospheric 

 currents and depressions. To reach a positive conclusion on this point, how- 

 ever, one must carefully consider all of the elements which enter into the 

 phenomenon, particularly the degree of ionization of the air and the intensity 

 and character of the electric field. 



Commenting on the above, G. Lemoine expresses the opinion that If frequent 

 and prolonged artillery discharges have any influence on rainfall it is only in 

 connection with light rains. 



Does violent cannonading induce rainfall? Sebebt {Compt. Rend. Acad. 

 Sci. [Paris], 16J, {1917), No. 18, pp. 663-069; abs. in Rev. Sci. [Paris]. 55 

 {1917), No. 10, p. S17). — Referring to discussions of this subject by De.slandres 

 and Lemoine, noted above, a question is raised as to whether intense cannonad- 

 ing does not create atmospheric disturbances which may induce heavy and pro- 

 longed rainfall. The author is of the opinion that the subject is of sufticient 

 importance to warrant careful investigation in certain restrictetl areas by 

 meteorological bureaus and agricultural experiment stations. 



Investigation of the influence of climatic conditions on the composition 

 of plant oils, G. V. Piguucvski (/Jiur. Russ. Fiz. h'liiin. Obshch., 4S {1916), pp. 

 324-341; abs. in Jour. Chcm. Soc. [London], 112 {1917), No. 653, J, p. 189).— 

 " Evidence is adduced showing that among plants belonging to one and the 

 same subfamily the iodiu number of the essential oil increases as the geo- 

 gi-aphlcal distribution of the plant extends farther toward the north." 



The past winter, C. Harding (Nature [London], 99 {1917), No. 2484, pp. £94. 

 295). — The characteristic features of the five months December, 1916, to April. 

 1917, which was an abnormally cold and wintry period generally over the 

 British Islands, are briefly reviewed Similar conditions prevailed over western 

 and northern Europe. 



SOILS— FERTILIZERS. 



Soil moisture and plant succession, G. D. Fult.kk {Trans. III. Acad. Sci., 7 

 0914)- PP- 6S-7S). — Data representing the range of soil moi.sture in the upper 

 subterranean strata of the vegetation of various associations are reported. 



" The rate of evaporation in the cotfeonwood dune association, both by its 

 great amount and by its excessive variation, seems a quite sufficient cause for 

 the xerophytic character of the vegetation and for the absence of undergrowth, 

 in spite of the constant presence of growth water. The pine and oak dune 

 association resemble one another closely in their supply of growth water. The 

 former is slightly more xerophytic during the midsummer weeks. The amount 

 of growth water in tlie various associations varies directly with the order of 

 their occurrence in the succession, the pioneer being the most xerophytic. 

 The ratios between the evaporation and growth water in the beech-maple 

 forest, oak-hickory forest, oak dune, pine dune, and cottonwood dune as.so- 

 ciatlons have been sho^^^l to have comparative values of 100. 65, 20, 17, and 15, 

 respectively, and the dlfi'erences thus indicated are sufficient to be efticient 

 factors In causing succession." 



Eight references to literature bearing on the subject are appended. 



Evaporation and soil moisture in forests and cultivated fields, J. F. 

 Gboves {Trans. III. Acad. Sci., 7 {1914K pp. 59-67, fiya. 5). — Experiments on 



