102 JOUENAL OF THE KOYAL HDKtldULtURAL SOCIETY. 



NOTES AND ABSTEACTS. 



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Abelia rupestris. By A. Heydt {Gartenflora, vol. Ix. pt. xx. 

 p. 447). — Abelia rupestris likes a half -shady position, in a well-manured 

 soil. To induce a bushy habit, cut back the growth to one-half every 

 spring-. A slight protection in winter is desirable. — S. E. W. 



Absorption of Food Substances and Poisons thpoug-h Leaves. 



By Alfred J. Ewart {Jour. Agr. Vict. p. 619; Sept. 1911).— If a drop 

 of a very dilute solution of potassium nitrate be placed upon a beech leaf 

 and covered with a small bell- jar so as to check evaporation, when the 

 drop finally disappears no crystals are left behind on the surface of 

 the leaf; whereas, if the drop is allowed to evaporate rapidly, a little 

 crystalline efflorescence is left behind, owing to the fact that the salt 

 had not time to be absorbed before the water had evaporated. 



Again, if the leaves of a plant happen to have become pale, 

 as sometimes occurs owing to a deficiency of iron in the soil 

 or to a difficulty in absorbing it, then merely painting the pale surface 

 of the leaf with a dilute solution of chloride of iron will restore the 

 green colour temporarily or permanently to the leaves so treated. 



An instance of the absorption of a poison is that of copper sulphate 

 solution, which adheres long enough to the charlock leaves to be 

 absorbed by them and to cause their death, whereas the solution runs 

 off the grass leaves without affecting them to any appreciable extent. 



Superphosphate applied to the leaves of mustard and soy beans 

 in the form of powder was found to destroy them. 



Mustard and soy beans treated with nitrogenous food (nitrates, 

 ammonium salts, asparagin), also with phosphates (super-phosphate, 

 basic slag), could not absorb through the leaves sufficient 

 to make good a deficiency in the soil, however carefully and thoroughly 

 these substances were applied to the leaves. 



On the other hand, potassium salts were readily absorbed through 

 the leaves of mustard plants in the form of potassium sulphate, and 

 preferably as potassium chloride in the case of soy beans. 



Thus in Professor Hiltner's pot experiments : Without potassium 

 the yield was 15 grammes ; with chloride of potassium applied to the 

 soil, 38 grammes ; with potassium sulphate applied to the soil, 45.5 

 grammes; and with it sprayed on the foliage, 43.5 grammes. 



Professor Hiltner (Professor of Agriculture at the University of 

 Munich) sprayed ' Magnum Bonum ' potatos that were badly attacked 

 by leaf -curl disease {Macros poriuni Solani) with various solutions with 

 the following results : — 



