FOREWORD 



By Professor Sir Howard W. Florey, 



F.R.S., M.D., PH.D., M.A., F.R.C.P. 



President of The Royal Society, London 

 Professor of Pathology, University of Oxford 



Mr. Edward Gurr is known to many histologists and cytolo- 

 gists for the excellent reagents he produces and for his unfailing 

 courtesy and helpfulness in dealing with the questions put to him 

 about stains and staining methods. He has for many years made a 

 study of the chemistry of dyes, and at the same time he has 

 extensively studied their histological applications on which he has 

 written a number of successful books. 



In this new book he embodies his long experience on both the 

 theoretical and practical aspects of staining. It should prove of 

 the greatest value to all concerned with the art and mechanism of 

 biological staining, and I wish it every success. 



H. W. Florey. 



