NOTES AND ABSTRACTS. 



603 



During Irrigating Period. — Indian com, 144 lb., and after irrigation 

 104 lb. ; potato lands, 110 lb. before and 94 lb. after irrigation; alfalfa, 

 34 lb. and 38 lb. ; fallow, 174 lb. before and 130 lb. after irrigation. 



During the Fall. — Indian corn, 63 lb. ; alfalfa, 32 lb. ; fallow, 151 lb. 



The nitric nitrogen tends to accumulate in the lower foot sections 

 (depths of 7 to 10 feet) during winter and spring. The concentration 

 is low on alfalfa land. Cultivation seems to increase nitric nitrogen 

 contents, but only temporarily. ' 



The concentration decreases steadily from period to period in potato 

 and Indian corn land, but is nearly constant in alfalfa and fallow lands. 

 Under oats the nitric nitrogen disappears rapidly during the last few 

 weeks of growth. — G. F. S.-E. 



Nitrogen Cycle and Soil Org-anisms. By S. F. Ashby (Bull. 

 Dep. Agr. Jamaica, vol. i. 1909, p. 2 ; 4 figs.). — A clear statement of 

 the present knowledge of nitrogen fixmg and separating organisms in 

 the soil of Jamaica. — E. A. B. 



Nitrogen, Electric Fixation of Atmospheric. By S. C. Stuntz 

 {U.S.A. Dep. Agr., Bur. of Soils, Bull 63).— This bulletin gives a 

 brief description of the manufacture and uses of the two new nitrogenous 

 fertilizers, basic calcium nitrate and calcium cyanamide, and a very 

 complete and valuable list of references to literature dealing with these 

 substances, including a list of articles giving the results of manurial 

 trials with them. — F. J. C. 



Nutritive Salts, Ratio of Absorption of. By 0. Schreiner 



and J. J. Skinner {Bot. Gaz. vol. 1. pp. 1-30; with 9 figs.; July 

 1910). — These experiments were carried out with wheat seedlings 

 grown on perforated sheets of hard rubber or aluminium discs and kept 

 floating (by means of cork floats) on water. 



No fewer than sixty-six different solutions were used, consisting of 

 calcium acid phosphate, sodium nitrate, and potassium sulphate in 

 various proportions. An ingenious graphic method of remembering the 

 various proportions is explained in the paper.^ It consists roughly in 

 putting the three salts used at the corners of an equilateral triangle. 

 Each side of the triangle is divided into ten equal parts. Lines are 

 then drawn parallel to the sides through the points. The original points 

 and the intersections of these lines are numbered. The numbers corre- 

 spond to the strengths of all possible combinations of the three salts, 

 which differ by 10 per cent. 



The results showed that the best growths occurred with solutions 

 containing between respectively lU to 30 per cent, potash, 30 to 60 per 

 cent, nitrate, and 30 to 60 per cent, potash. 



The seedling plant requires high amounts of potash and low of 

 phosphate.— G. F. S.-E. 



Nymphaea Lotus. By F. Henkel (Gard. Chron. xlvii. (1910), 

 p. 83; Feb. 5; fig.). — Seeds were received by the author from the 



