226 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
recognition of the different parasites, and the symptoms of disease 
and its prevention and cure, are all sufficiently dealt with and 
brought up to date. 
Chapter VI., ‘Protection against Injurious Influences in 
Soil and Atmosphere,” is the title of the concluding chapter of 
Part IV. This chapter is an exceedingly interesting and 
important one. Generally speaking, it consists of three sections 
—(1) Protection against non-parasitic diseases of trees; (2) Pro- 
tection against wetness and aridity of soil; (3) Protection 
against injurious atmospheric influences. It stands to reason 
that the forester cannot do much to alter the unfavourable 
physical and climatic conditions of soil and atmosphere, hence 
protection resolves itself into a question of selecting suitable 
species and treating them in a manner suitable to the concrete 
conditions of the locality. The chapter commences with a very 
good discussion concerning pre-disposition to disease. ‘This is 
followed by a description of diseases due to unsuitable soil and 
situation, which, together with the description of diseases due 
to external injuries, complete the first section. Protection 
against wetness and aridity of soil is principally a question of 
drainage on the one hand and the fixation of shifting sand on 
the other. Both these questions are dealt with in a very 
satisfactory manner. Finally, we come to protection against 
injurious atmospheric influences. Those injurious influences 
are wind, extremes of temperature, drought, aqueous precipita- 
tions, lightning, and atmospheric impurities. Each of these 
factors is considered in detail, and, where possible, remedies 
and preventive measures are described. ‘The forester will find 
this a very useful chapter to consult in cases of difficulty. 
Part V. of the work is devoted to a consideration of the 
Management and Valuation of Woodlands. 
The first chapter deals with ‘‘The Theoretical Principles of 
Wood Management,” the second with ‘The Measurement of 
Timber-Crops,” and the third with “The Formation of Working- 
Plans, or the Practical Application of the Theoretical Principles.” 
Chapter IV. deals with “ Book-keeping on Woodland Estates,” 
and Chapter V. with “The Valuation of Woodlands.” 
Of the British literature on the subject, Dr Nisbet draws upon 
Schlich, Brown, Grigor, and Bright, as well as upon his own writings. 
In Chapter I. the author discusses what is implied in the 
term, ‘‘ Normal Growing Stock or Capital in Wood,” and the 
