308 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



The writer mentions a salt-water lake in the North of Africa in 

 which, during hot weather, the evaporation is so much faster than the 

 supply of water from the sea that its contents become too salt even 

 for the seaweeds, which die from that cause. — M. L. H. 



Spruce Disease. By P. Spaulding (Mycologia, iv. p. 151 ; May 

 1912). — Attention is called to a disease of Picea excelsa resulting in the 

 defoliation of even large trees. It is caused by the fungus Phoma 

 piciena, which also attacks Picea rubra. Burning the fallen needles 

 and spraying with fungicides to prevent the spread of the disease are 

 recommended. — F. J. C. 



Spruce, Protecting from Frost. By W. Hall (Trans. Scott. 

 Arbor. Soc, pp. 51-53 ; July 1913). — Alder planted with young 

 spruce in places where the soil is very wet in winter have proved 

 an excellent protection. In another case birch has also proved a 

 protection. — W. G. S. 



Strawberries, Forcing by Etherization. By M. G. Bultel 



(Jour. Soc. Nat. Hort. Fr., ser. iv., xiii., p. 212 ; April 1912). — An article 

 on forcing strawberries by two methods, viz. etherization and by 

 immersion in hot water. The writer gives comparative tables showing 

 the decided advantage in early maturity gained by the treatment 

 with ether, and though he points out facts which would seem to be 

 against the alternative method of hot water baths he promises to 

 investigate this matter again another season and to publish the results 

 in the same detail. His theory at present is that it will be found 

 impossible to immerse the dormant shoots of the plants without com- 

 pletely soaking the whole ball of earth, and so much moisture to the 

 roots at that stage of their growth is considered to have bad effects. 



M. L. H. 



Sulphur, The Fertilizing Action of (Rev. Hort. Beige, No. 20, p. 328, 

 Oct. 15, 1912). — A communication by Messrs. Boulanger and Dugardin 

 to the Acad6mie des Sciences «e.e.ms to show that the addition of small 

 doses of flowers of sulphur to potting soil has beneficial effects. The 

 sulphur does not act directly, but it stimulates the action of useful 

 microbes in the soil, and as through such action additional nitric 

 matter is made assimilable by the plants, more organic nitric manure 

 must be supplied to make up for this increased consumption. 



M. L. H. 



Tobacco Extracts, Comparative Value as Insecticides. By W. O. 



Hollister (Jour. Econ. Entom., v. pp. 263-267 ; June 1912). — 

 Tobacco is one of the earliest substances to be recommended as an 

 insecticide, having been used certainly as early as 1763 against aphides, 

 in the forms both of tobacco water and tobacco powder. It is still 

 one of the most useful contact sprays we have. 



