THE OPPORTUNITY OF THE AGRICULTURIST 693 



Colleges such as this are intended to remedy the state of 

 things complained of by the poet ; to attune their students to 

 a real appreciation of Nature. Your gain will be in proportion 

 to the extent to which you avail yourselves of the multitude of 

 opportunities the College affords for the study of methods and 

 the cultivation of the faculty of insight. 



Let me now touch on some of the problems which should 

 come under your notice on the vital side. The amount of 

 carbon dioxide in our atmosphere is but three parts in ten 

 thousand — yet this is the whole trading capital of the agricul- 

 turist the wide world over. That so much can be made of so 

 little is very wonderful ; and when we learn something of the 

 mechanism by which Nature effects her purpose, it borders on 

 the miraculous. Watching on a sunny day in spring the quivering 

 leaves in a woodland district or the waving blades in a wheat 

 field, we may well fancy that we are contemplating an ideal state 

 of lazy enjoyment : the forces at work, the ceaseless activity of 

 the leaf-surfaces, are in no way apparent. The plant is thought 

 of merely as growing. Oliver Wendell Holmes's beautiful lines : 



. . . God has made 

 This world a strife of atoms and of spheres ; 



With every breath I sigh myself away 

 And take my tribute from the wandering wind, 



To fan the flame of life's consuming fire — 



are not only descriptive of the process of animal respiration 

 regarded as a destructive process but also of plant respiration 

 regarded as a constructive process — tribute being taken by the 

 plant from the wandering wind of its x^f ^ of carbon-containing 

 gas as well as of a certain modicum of oxygen. 



It is taught in the schools that under the influence of 

 sunlight and with the assistance of the green colouring-matter, 

 the carbon dioxide which the plant inhales is resolved into 

 carbon which is retained and oxygen which escapes. The 

 warmth displayed and dissipated when carbon and oxygen 

 unite must in some way be recovered and restored to the 

 system : the sun affords the necessary energy ; hence it is 

 that we regard vegetable matter as bottled-up sunshine. At 

 present the nature of the initial process is entirely unknown to 

 us ; we can only form very general ideas as to the changes 

 which supervene. Personally, I incline to the view that it 

 will eventually be recognised that carbon dioxide is only 



