PREFACE 



Vetera et Nova, or ' Old and New,' fitly describes the 

 character of the following pages and the materials used 

 in their production, as well as the results arrived at in 

 the way of constructive effort by the re-arrangement 

 of them on lines dictated by re-interpretation of their 

 individual and combined meaning when viewed apart 

 and when placed in fresh relationships. The ' old ' 

 has thus been used to construct the ' new,' and whether 

 the result may turn out a success remains to be seen, 

 and whether so much fault-finding has been justified 

 remains to be tested by the application to it of the 

 usual canons of criticism and practical application of it 

 to everyday requirements of those engaged theoretically 

 or practically in working the departments of knowledge 

 involved in the subjects dealt with. 



No department of knowledge can remain stationary 

 intrinsically, and much less so when regarded as an indis- 

 pensable part of universal knowledge ; it must therefore 

 move forwards or backwards in obedience to forces work- 

 ing from within, and be moved from without according 

 to its specific position in the great commonwealth of 

 knowledge and the general alteration in relationship 

 to its various departments. In the latter respect the 

 department of biological physics, it seems to us, has not 

 changed its position to the extent that the movements 

 of some of its later offshoots require in order that the 



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