296 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Niagara Electric. By M. A. Laforest {Jour. Soc. Nat. Hort. Fr.\ 

 4th Series, vol. xiii., p. 572, Sept. 1912). — The apparatus called by this 

 name, installed at intervals around a certain area, was supposed to be 

 going completely to protect that area from hail. Later experiences, 

 however, have proved that it is quite ineffective for this purpose. 



M. L. H. 



Nicotiana Tabacum, Correlation and Inheritance in. By 



H. K. Hayes (U.S.A. Exp. Stn. Conn., Bull. 171, 45 pp. ; 5 pi.). — The 

 results of experiments made upon different Tobaccos with a view 

 of studying the inheritance of quantitative characters and of corre- 

 lation. The very difficult point of separating variations caused by 

 culture and those which are truly inherited is discussed, but no very 

 definite conclusion is arrived at. The correlation co-efficients between 

 number of leaves and the height of a plant, number of leaves and 

 leaf area, &c, are given for a large number of crosses, but are obviously 

 impossible to quote here without the context. — E. A. Bd. 



Nitrification in Different Soils. By H. Fischer (Landwirtsch. 

 Jahrb. xli. 755; 1912). — The author found that nitrification takes 

 place more rapidly in a somewhat heavy soil than in a light sand. 

 One of the causes is evidently the lack of lime in the latter soil. On 

 the other hand, the formation of ammonia is greater in light than in 

 heavy soils. The theoretical quantity of lime calculated as being 

 necessary for the nitrification of a given quantity of ammonia does 

 not in reality suffice for complete nitrification, this process attaining 

 its maximum rapidity with about three times the theoretical amount 

 of lime. Nitrification is favoured by the supply of organic materials 

 such as sugar or peat-decoction, but when too much organic material 

 is supplied denitrification takes place, especially in light soils. The 

 author's experiments on the bacterial content of three originally 

 similar soils treated differently for three years (unmanured, ammonium 

 sulphate added, sodium nitrate added) lead him to the conclusion that 

 the bacterial differences between such differently treated soils are 

 relatively slight, and that a much more natural expression of the 

 bacterial character of a soil is given by actual soil experiments than 

 by water-cultures. — F. C. 



Nitrogen in Five Years' Experiment with Legumes, The Gain in 



(U.S.A. Exp. Sin., Rhode I., Bull. 147, 1911). — Crops grown, 

 Crimson Clover, Cowpea, Soybean, and Vetch. 



The increase amounted to 1 ton of nitrogen to the acre, seven- 

 tenths being removed by the crops, the remainder left in soil. 



The value of legume crops to farmers is calculated at £13 per 

 annum from each acre. — C. P. C. 



Onion Couch. By L. M. Underwood (Jour. Agr. Sci. iv. pp. 270- 

 272 ; Jan. 1912 ; figs.). — Seeds of the onion couch (Arrhenatherum 

 bulbosum) and of the common form of the tall oat grass (Arrhenatherum 



