516 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



in the grounds, and the other is in his too free use of cement among the 

 stones, which is unsuitable in appearance and not really so good for the 

 plants.— If. L. H. 



Alpines, should they be manured? By S. Arnott (Garden, 

 April 17, 1909, p. 190). — The answer given is that manures may be 

 valuable to alpines, but all do not require them, and not every kind of 

 manure is suitable, nor should they be used very often. Stable and cow 

 manure should be very old and decayed. Before applying (in spring) 

 they should be dried and powdered ; for artificials a mere pinch is 

 enough ; bone manure should not be given to plants which dislike lime. 

 A liquid manure recommended for watering in summer is composed 

 of 80 gallons of water and 90 grains each of nitrate of lime, sulphate 

 of magnesia, and nitrate of potash. 



E. H. Jenkins (Garden, May 8, 1909, p. 224) confirms this opinion, 

 but he states that woolly leaved subjects, like the Androsaces, do not 

 require manures, and the Onosmas and Omphalodes Lucilliae are 

 easily poisoned by organic manures, and for* alpines generally quick- 

 acting or highly concentrated manures should be avoided. — H. B. D. 



Ammonium Salts, Direct Assimilation by Plants. By H. B. 



Hutchinson and N. H. J. Miller (Jour. Agr. Sci. iii. (1909), p. 179).— 

 When soils continually receive ammoniacal manures, they eventually 

 become acid and the formation of nitrates by nitrifying organisms is 

 prevented, yet many plants are able to develop, thus suggesting that they 

 are capable of absorbing and making use of ammonium salts. Much 

 differeuce of opinion has been expressed by agricultural chemists and 

 vegetable physiologists as to whether ammonia could be made use of, and 

 it is generally supposed that nitrates only can be assimilated, but the 

 present paper shows that many plants are able to produce normal growth 

 when supplied with nitrogen in the form of ammonium salts, under 

 conditions which completely exclude the possibility of nitrification. 

 Plants, however, differ in this respect, and some appear to prefer nitrates, 

 while others are able to grow equally well, whether supplied with 

 ammonium salts or with nitrates. Some, again, prefer ammonium salts 

 to commence with and nitrates later on. Plants which take up nitrogen 

 exclusively in the form of ammonium salts generally contain distinctly 

 higher percentages of nitrogen than when supplied with nitrates. It is 

 suggested that possibly the high percentages of nitrogen in leguminous 

 plants may be due to the nitrogen, or most of it, being assimilated in a 

 form more suited to the rapid production of proteids than nitrate. 



F. J. C. 



Anaesthesia of Plants. By P. Noel (Le Jard., vol. xxiii. No. 532, 

 p. 126 ; April 20, 1909). — An interesting application of M. Johannsen's 

 now well known theories re Etherization and Forcing has been made in 

 Normandy. Finding that the late frosts invariably destroyed his crop of 

 plums, M. Noel made a hole 40 inches deep at the- foot of the tree and 

 poured in 200 cc. of chloroform or ether. The blossoming was delayed 

 a fortnight and the trees did not flower till the frosts were over. There 



