1917] SOILS FERTILIZERS. 717 



limited extent (not exceeding 5 per cent) by promoting the condensation of 

 nqueous vapor. There appears to liave been no change in the level of tlie under- 

 ground water during the last 50 years, except sucli as depends upon the rain- 

 fall. Apparently in most Provinces there has been no serious damage to the 

 flow of rivers and no great injury to cultivation as a result of floods duo to 

 forest denudation. There are, however, local exceptions, and much flood damage 

 has been done in the Punjab, in Bengal, and in .tVssam. 



Rainfall and giinfire, A. Angot {Covipt. Rend. Acad. Agr. France, S {1917), 

 No. 18, pp. 501-50S; rev. in Nature [London}, 99 {1911), No. 249S, pp. 467, 46S; 

 Sci. Amer. Sup., SJf {1917), No. 2180, p. 227).— This paper deals with the his- 

 torical as-pects of the subject, reviews the various theories advanced, and 

 adduces evidence to show that there is no causal relation between gunfire and 

 rainfall. 



Correlation between atmospheric phenomena and the yield of crops {Rev. 

 Sci. [Paris], 55 {1917), No. U, p. //36).— This is a brief note on studies by 

 Marenghi on tlie influence of precipitation on the yield of alfalfa, in which a 

 record was kept during 10 years of the spring rainfall and of the yield of the 

 crop. The coefficient of correlation was found to be 0.49 for the particular 

 period and place in which the studies were made. 



Phenological observations in the British Islands, J. E. Clakk and H. B. 

 Adames {Quart. Jour. Roy. Met. Sac. [London], 43 {1917), No. 183, pp. 285-316, 

 figs. 2). — Observations from December, 1915, to November, 1916, at 117 stations 

 on wild plants, birds, and insects are summarized. Tentative isophenal lines 

 or zones similar to those of Ihne for Continental Europe are shown for several 

 flowering plants for periods of 120 (April 29), 130 (May 9), and 140 days (May 

 19) for the British Isles. The usual data for farm crops are not included, 

 although the status of farm work and crops at different dates is noted. 



Climatological studies. — German East Africa, H. G. Lyons {Quart. Jour. 

 Roy. Met. Soc. [London], 43 {1917), No. 182, pp. 175-195, pis. 8, figs. 5).— This 

 article is based upon observations covering the 20 years from 1892 to 1911. 



" On account of its position close to the equator most of the colony receives 

 heavy tropical rains in the wet season, while the drier northeasterly and south- 

 easterly air currents of northern and southern Africa, respectively, sweep over 

 it and give rise to dry seasons which are in some parts of several mouths' 

 duration and of considerable aridity." Seasons, as understood in the Temperate 

 Zone, do not exist, but instead there is an alternation of the dry season and the 

 rainy season which divides the year and determines the cycle of agricultural 

 operations. The coastal region, as a result of air currents from the Indian 

 Ocean, has a heavier rainfall than many parts of the interior. 



Such climatic variations as occur are largely those due to the physical charac- 

 ter of the country. The climatic conditions of each district are discussed in 

 some detail with reference to vegetation. 



SOILS— FERTILIZEES. 



The soil solution obtained by the oil pressure method, J. F. Morgan {Soil 

 Sci., S {1917), No. 6, pp. 531-545). — Experiments at the Michigan Experiment 

 Station with the paraffin oil displacement-pressure method are reported. In 

 this method the solution is displaced by forcing paraffin oil by pressure through 

 the soil. 



It was found that " the paraflSn oil pressure method furnishes in most cases 

 plenty of solution for the necessary analytical work. In sandy soils as high as 

 74 per cent of the moisture present in the soils was obtained. A large amount 



