SOILS — FERTILIZERS. 123 



the water table varied generally with the Elbe but did not show the spasmodic 

 variations. 



A study of some water tables at Giza, W. L. Balls (Cairo Sci. Jour., 8 

 {1914), A'o. 92, pp. 102-111, pis. 2). — The results obtained by measurements in 

 17 tube wells ou au area of 30 acres near Cairo, Egypt, are presented graphi- 

 cally and discussed. 



With the exception of one hole which was bored G meters, the holes for the 

 tube wells wore bored 3 meters deep. JNIeasurements were taken weekly and 

 daily, each measurement being computed on the basis of a common bench mark 

 of known elevation. In taking measurements a boxwood scale 4 mm. thick and 

 5 mm. wide and weighted at its lower end by a loose lead bob of 5 cc. volume 

 was lowered into the well on the end of a light steel chain marked at meter 

 intervals and the wetted length noted. A correction for the rise in water level 

 due to the displacement of the scale and bob was necessary. 



The extreme complexity of the subsoil structure is said to have caused very 

 variable behavior in the different wells. Different wells were differently 

 affected by surface irrigation, by seepage from land channels, by infiltration 

 from a canal, by the Nile flood, and by the downflow of water from Upper 

 Egypt coming from canals, out of the river, or from surface irrigation. 



The well level in freely permeable soils rose higher during 1913 than the Nile 

 flood. The water table, instead of being stagnant and quiet, responded con- 

 tinually to hydraulic impulses from all directions and from unknown distances. 

 It was never at rest except in isolated clay basins and even there was slightly 

 troubled by meteorological changes. 



It is further concluded that irrigation has increased the level of the natural 

 water table of Egji^t. 



A list of references to related works is appended. 



Note on seasonal variation in the composition of drainage water, F, 

 Hughes {Cairo Sci. Jour., 8 {1914), No. 94, pp. 159, 160).— Weekly analyses of 

 drainage water from irrigated soil showed the maximum amount of dissolved 

 solids in July and the minimum in November. The chlorids showed a nearly 

 constant relation to the total solids, and the alkalinity was extremely constant. 

 As the Nile rises the salinity of the drainage water is said to decrease, and to 

 increase during the period when the canals are closed for the winter. 



Decomposition of soil carbonates, W. H. MacIntire {U. 8. Dcpt. Agr., Jour. 

 Agr. Research, 3 {1914), No. 1, pp. 79, 80). — This is a brief note on the investi- 

 gations previously noted (E. S. E., 31, p. 815). 



The nitrogen content of soils of Scania, Sweden, M. Weibull {K, Landtbr. 

 Akad. Handl. och Tidskr., 53 {1914), No. 2, pp. 65-93; ahs. in Internat. Inst. 

 Agr. [Rome], Mo. Bui. Agr. Intel, and Plant Diseases, 5 {1914), ^o. 7, pp. 

 859-863). — The variation in the nitrate content of soils under different methods 

 of culture and fertilizing was traced. The nitrate content never exceeded 22 

 parts per million in cropped soils. In fallow soils it rose to 33 parts per million. 

 Under beets it was 14 parts and under wheat and peas from 8 to 9 parts. The 

 nitrate content was low in spring but generally increased in early summer. 

 Cultivation and manuring increased the nitrates. As a rule the soils examined 

 did not contain enough nitrates to meet the requirements of growing crops. 



It is concluded that if under normal climatic conditions the nitrate content 

 falls to 2 parts per million before August the need of applying nitrogenous fer- 

 tilizers is indicated. 



Experiments on the rate of nitrification, R. M. Beesley {Jour. Chem. Soc. 

 [London], 105 {1914), No. 618, pp. 1014-1024, figs. 3; ahs. in Internat. Inst. Agr. 

 [Rome], Mo. Bui. Agr. Intel, and Plant Diseases, 5 (1914), No. 7, p. 863).— The 

 75575°— No. 2—15 3 



