PREFACE VI 1 



PREFACE TO THE FOURTH EDITION 



To this edition a new chapter has been added and very consider- 

 able additions made throughout the work, with a view of improving 

 its usefulness and keeping the matter up to date. 



It is gratifying to find that the volume is highly appreciated 

 by teachers and students in all countries wherever English is 

 spoken. 



JOHN PERCIVAL. 



Jem. 1910. 



