PREFACE TO THE EIGHTH EDITION. 



issuing the Eighth Edition of this Work 

 on the MICROSCOPE, I may say that it has 

 been thoroughly revised and for the most 

 part rewritten. Eight carefully and 

 beautifully executed Plates are added, 

 which were drawn by Mr. Tuffen West from 

 natural objects, engraved and printed by Mr. 

 Edmund Evans in his usual excellent manner. 



The Author cannot but express his grateful surprise 

 at the extraordinary popular reception which his book 

 has met with : a sale of fifty thousand is an unpre- 

 cedented event for a work of the kind. This circum- 

 stance is extremely gratifying to him, because it affords 

 reasonable grounds for believing that his work has 

 been useful, and encourages renewed effort to make 

 the volume still more acceptable. It has been his 

 endeavour to bring the information contained in its 

 pages up to the most Decent discoveries ; although, in 

 a daily progressing field of science, it is almost im- 

 possible to keep pace with the advance of knowledge 

 in all its ramifications. 



1, BEDFORD SQUARE, 

 October, 1867. 



