METEOROLOGY WATER. 719 



slow; but after tbe formation of the ears, up to harvest, they grow i-apidly in 

 favorable years. Eain is the most important factor, and the critical period is 

 within the 10 days preceding the formation of the ears, generally in June." 



Similar studies were made with millet, the results of which have already 

 been noted from another source (E. S. R., 23, p. 117). 



Action of soil moisture on the growth of oats, I. A. Pulman {Esheg. Dept. 

 Zenil. [Russia~\, 1909, pp. 7//, 75; abs. in Intemat. Inst. Agr. [Rome], Bui. Bur. 

 Agr. Intel, and Plant Diseases, 1911, No. 4, P- 819). — Pot experiments at the 

 Bogoroditsk experiment station showed that the optimum results were obtained 

 with a constant soil moisture content of 34 per cent during the period from the 

 appearance of the head to the setting of the grain, which is considered the 

 critical period of oats; that a decrease in moisture from 34 to 24 per cent at 

 this period decreased the yield 32 per cent; that an increase of moisture from 

 24 to 34 per cent during this period increased the average yield 11 per cent; 

 and that the number of grains is larger but their size smaller with a constant 

 soil moisture content during this period of 24 per cent. 



The fertilizing value of rain and snow, F. T. Shutt (Ottatva Nat., 25 

 (1911), No. 6, pp. 99, 100). — In continuation of observations previously noted 

 (E. S. R., 24, p. 417) it was found that the rainfall at the Ottawa Experimental 

 Farm during the year ended February 28, 1911, was 10.07 in. and the snowfall 

 7.3 in., representing a total precipitation of 26.97 in., about 10 in. below the aver- 

 age for the locality. This precipitation furnished 5.271 lbs. of nitrogen per acre. 



Of the average nitrogen (4.424 lbs. per acre) for the 4 years 1908-1911, 84 per 

 cent was supplied by the rain. Of the total nitrogen, 3.733 lbs. was in the form 

 of ammonia. 



[Composition of rain water, British .Guiana], J. B. Hakeison (Rpt. Expt, 

 Ayr. Work Dcpt. Sot. and Agr. [Brit. Guiuiia], 1909-10, pp. 15-18; abs. in Jour. 

 Chem.. Soc. [London], 100 (1911), No. 584, II, PP- 530, 531).— The average 

 annual rainfall at Georgetown. 1890 to 1909, was 99.27 in., furnishing 1.01 lbs. 

 of nitrogen as ammonia, 1.89 lbs. of nitrate nitrogen, and 129.2 lbs. of chlorin 

 per acre. Of the total nitrogen, therefore, 34.8 per cent was in the form of 

 ammonia and 65.2 per cent in the form of niti'ates. 



Further experiments on dew ponds, E. A. AIaetin (Geogr. Jour., 36 (1910), 

 No. 4, pp. 439-464, figs. 4)- — In continuation of previous observations on this 

 subject (E. S. R., 22, p. 118), the author reached a positive conclusion that 

 " rain is undoubtedly the all-important replenisher of these, as of all ponds 

 which are not fed by springs," and that dew plays an insignificant part in this 

 process. 



The geology of water supply, H. B. Woodward (London, 1910, pp. XII +339; 

 rev. in Nature [London], 87 (1911), No. 2181, p. 206). — In this book an attempt 

 is made to set forth clearly the main geological features to be taken into account 

 by the engineer, chemist, or physical geographer in dealing with the problem of 

 vv'ater supply, mainly in their api)lication to conditions prevailing in the British 

 Isles. A bibliography of the subject is appended. 



The bacteriology of ice, E. O. Jordan ( Cold Storage and Ice Trade Jour., 42 

 (1911), No. 1, pp. 31, 32). — Experimental data are summarized which lead to 

 the conclusion that under suitable conditions freezing is a purification process 

 and that any bacteria which remain in ice tend to disappear on storage. " Nat- 

 ural ice is habitually stored for a considerable period, and this fact materially 

 increases its safety from the public health standpoint. After 3 or 4 months the 

 danger from ice cut from even highly polluted water would be very slight, and 

 after 6 months' storage would be practically neglicihle." 



The significance of flora and fauna in maintaining the purity of natural 

 waters, M. Marsson (Mitt. K. Pritfungsanst. Wasserrer. u. Abwdsser. Berlin, 



