318 JOURKAL OF THE ROYAL HORTICULTURAL SOCIETY. 



ammonium salts, calcium salts, and magnesium salts all appear to 

 increase the solubility of calcium carbonate. — F. J .C. 



Soils, Absorption of Vapours and Gases by. By H. E. Patten 

 and F. E. Gallagher (U.S.A. Dep. Agr., Bur. of Soils, Bull. 51 ; April 

 1908). — A summary of previous investigations on the power of soils to 

 absorb vapour of water and other gases is given, and an account of work 

 undertaken with a view to an increase of our knowledge of the extent of 

 this absorption and the conditions under which it takes place. The 

 absorptive capacity of a soil for water vapour is generally higher, the finer 

 the texture of the soil, and the greater the content of humus, and, in 

 general, productive soils have a great capacity for absorbing water vapour. 

 Other gases are absorbed at different rates, the rates, as with water vapour, 

 decreasing with a rise of temperature, with a diminished pressure of the 

 gas, and as the saturation point of the soil is approached. The absorption 

 of water vapour by the soil is accompanied by an evolution of heat (in 

 excess of that given up by the vapour on condensation) and a consequent 

 rise in soil temperature. It is interesting to note that nitrogen is 

 absorbed from the air at a greater rate than oxygen (the exact converse 

 from what is observed in the case of water), while all soils absorb 

 appreciable quantities of ammonia from the air. — F. J. G. 



Soils, Moisture Content and Physical Condition of. By F. K. 



Cameron and F. E. Gallagher (U.S. A. Dep. Agr., Bur. of Soils, Bull. 

 50; January 1908). — The methods of moisture determination, &c, are 

 described, together with the experimental data upon which the conclusions 

 are based. It is shown that different (ordinary) plants require about the 

 same percentage of water in the soil to secure the best growths, but that 

 wilting occurs in different soils at very different percentage of water 

 according to the different composition of the soil. Thus wilting began to 

 occur when the percentage fell to 9 per cent, in a calcareous soil, but when 

 it fell to 34 per cent, in a peat soil. It is concluded that that percentage 

 of water in the soil " which makes for the greatest aeration, loosest 

 structure, and, in general, most favourable physical condition of the soil " 

 is the optimum for plant growth. — F. J. C. 



Strawberries, Climbing 1 . By F. Touraine (Le Jard. xxiii. 529, 

 p. 72; March 5, 1909; coloured plate). — 'Gemma,' ' Mirabilis,' ' Suavis,' 

 have already been described in these abstracts. In planting, the long- 

 close row is to be avoided. Break the soil up well, and see that the roots 

 are distributed and separated, not crushed together in a round hole. 

 Cover the plant well with soil. Water freely after planting. The object 

 being to obtain plenty of runners it is best at first to sacrifice the central 

 flowers. When enough runners have been established the flowers may be 

 allowed to develop. ' Gemma ' produces few runners ; hence they must 

 be cherished and covered with earth as soon as two or three leaves have 

 been developed. 1 Mirabilis ' and ' Suavis ' have more, so it is best to 

 pinch off the early runners, preserving them only from July onwards. If 

 at the end of a year any plant fails to climb, it should be removed in 

 August, and replaced by suckers from one of the fitter plants. This 

 process of selection is highly important in strawberry growing. — F. A. W. 



