1112 EXPERIMENT STATION RECORD. 



the amount, composition and other ciiaracteristics of the underground water by 

 j^eolof^ical formations and by counties. The rejtort is in [lart a revision of a 

 paper on the artesian well system of (Jeorj^ia. iiuhlished in l.S!)S. 



Dew ponds, G. IIubbaru {Jour. Roy. Soc. Arl.s, J7 {1900), \o. 2DS7, pp. 330- 

 34O). — The article tells what dew i)onds are, explains the conditions essential 

 to their eftlcient action, and discusses the possibility of their introduction with 

 advantajre into arid rejiions. Accurate data are too limited to draw positive 

 conclusions as to the latter point. S«h' also a previous note (K. S. li., 17, \). ^'ili). 



A phase of ground water problems in the West, W. C. Mkndkniiall {Ecou. 

 GcoL, -'1 (JHO'J), Xo. 1, pp. 3o-'i'), fign. 2). — This article is based upon observa- 

 tions on " the relation of the withdrawals of ground water by artilicial means 

 to the recharge from precipitation and run-off" in the San Bernardino Valley, 

 California, " where, during 8 or 9 years past, the total developed waters and 

 the total waters that rise naturally in springs have been measured twice an- 

 nually. The total water from both these sources, all of which is used for 

 domestic purposes or for irrigation, has increased slowly, although irregularly, 

 to kef»p pace with the increasing poi)ulation of the dependent communities, but 

 the most striking fact brought out by the measurements is the general increase 

 in the amount of developed water, accompanying an equally marked general 

 decrease in the natural waters; that is to say, the flow of springs has lessened 

 markedly as the yield of wells has increased. . . . 



" Detailed measurements have not been made for other of the many basins 

 that together constitute the valley of southern California, but there is no doubt 

 that were they to be had they would indicate about the same condition that 

 exists in the San Bernardino basin." 



The need of " constant I'ccords of fluctuations in ground water levels, for com- 

 parison with the average rainfall, or the average flow of the supplying stream," 

 is emphasized. 



The presence of nitrites and ammonia in drinking water, S. Van Eyk 

 {Phurm. Weekbl, J,5 {1908), A'o. .',1, pp. 1162-1165; abs. in Chem. Abs., 3 {190V), 

 No. 6, p. 682). — The occurrence of considerable amounts of nitrites in water 

 from a zinc-lined pump is reported. An investigation of the matter indicated 

 that the nitrites were due to the reduction of nitrates by the zinc. 



The removal of iron from well water, Peters {Ztschr. Jlijg. u. Infcktions- 

 l-rank., 61 (1908), No. 2, pp. 2'il-261 ; abs. in Chem. Abs., 3 {1909), No. 6, p. 

 6S2). — The method proposed is to pour into the well water which has been 

 standing for some time in the open air and has become thoroughly aerated. The 

 iron is precipitated by the oxygen thus introduced and the water may be pumped 

 out and filtered. 



The purification of ground waters containing iron and manganese, R. S. 

 Weston {I'roc. Amcr. Soc. Civ. Enyin., 3-J {1908), No. 10, pp. 1.U',-1S93, pis. 3, 

 figs. 8; 35 {1909), No. 2, pp. 1.50-166, fig. 1; abs. in Engin. Rcc, 59 (1909), No. 

 6, pp. l-'i6-l.',8, fig. 1; Engin. Digest. 5 {1909), No. 3, pp. 2.5i-2.56).— This article 

 explains that the method of deferrization which it is advisable to use in any given 

 case depends upon the comp(!sition and character of the water. A careful study 

 of the water is therefore a necessary preliminary to the application of etflcient 

 methods. Methods which have been employed with success are described. 

 The most important feature of all of these methods is thorough aeration. 



Chemical purification of drinking water in the country, J. Laurent {Jour. 

 Pharni. et Cliini., 6. ser.. 28 (1908), No. 9, pp. 392, 393; abs. in Rer. Sei. 

 [Paris], -'/? (1909), I, No. 5, p. 150). — I>irections are given for the application 

 of a method based upon the use of permanganate of potash and alum followed 

 by the addition of sodium hyposulphite and carbonate. 



