236 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



SO described in the catalogues. Even in the Kew Handbook 

 the two species of Himalayan silver firs, Abies Webbiana and 

 Abies Findrow are wrongly described as varieties of the same 

 species. Two of the Japanese Ficeas, F. Alcockiana and F. 

 ajaneiisis have hitherto been hopelessly confused by collectors ; 

 but it may be hoped that Mr Clinton Baker's volumes will go 

 far to set things right. The keys to the different descriptions 

 are most clear and precise. F. R. S. Balfour. 



The Soil : An Introduction to the Scientific Study of the Grojvth of 

 Crops, vii + 311 pp. and Index, 17 Illustrations and 

 numerous Tables. Fertilisers and Manures, xv + 384 pp. and 

 Index, 9 Illustrations and numerous Tables. Both by 

 A. D. Hall, M.A., F.R.S., Director of the Rothamstead 

 Experimental Station. London : John Murray. 5s. net each. 



Students of forestry and practical foresters will find much 

 that is both valuable and suggestive in the new edition of 

 Mr Hall's well-known work The Soil, the first edition of which 

 was published in 1902. The present edition follows the same 

 general plan as the first, but has been considerably extended, 

 some chapters having been entirely rewritten. 



As we should expect, the changes are most marked in the 

 sections dealing with the living organisms of the soil, and a 

 comparison of the two editions shows the great progress which 

 has been made in recent years in the investigation of the many 

 complex reactions brought about by the action of bacteria and 

 fungi in the soil. A problem of particular interest to the forester 

 is the method by which the accumulation of nitrogenous 

 compounds takes place in pasture lands and forest soils, and in 

 chapter vii. we have an admiraVjle summary of the present state 

 of knowledge of this most important subject. In subsequent 

 chapters the absorption of salts by the soil, the causes of 

 fertility and sterility, and the usefulness of soil surveys are 

 considered in detail. The work concludes with a useful 

 Bibliography. 



In Fertilisers and Mafiures, Mr Hall deals with the composition 

 and properties of manures and fertilisers, and the general 

 principles of manuring. There is a useful chapter on the 

 valuation of manures, and the work concludes with a highly 



