PREFACE TO THE SECOND EDITION 



I am very happy that the first edition of this book has met with so 

 kindly a reception; and I hope that this enlarged and revised 

 edition will be of greater service to medical research workers and 

 biologists all over the world. 



Many additions have been made to the subject-matter of the 

 book, and I wish to thank readers of the first edition for their 

 helpful suggestions, most of which have been incorporated in this 

 second edition. 



A section of histochemical methods has been added as it is felt 

 that this may be of service to various laboratory workers, including 

 those engaged in cancer research, who may be interested in the 

 rapidly expanding science of histochemistry, which offers a rich 

 field for investigation. 



The subject-matter of the book, as before, has been divided 

 into various headings: some of the methods which might have 

 been classified as " Cytological " have been placed under other 

 headings because the particular methods are more frequently 

 required by workers other than cytologists. For similar reasons, 

 methods which might have been transferred to the histochemical 

 section have been left under the same headings where they ap- 

 peared in the first edition. 



In addition to the standard works mentioned in the preface to 

 the first edition, reference has also been made to The Micro- 

 scopisfs Vade-Mecum edited by J. Bronte Gatenby and H. W. 

 Beams (J. & A. Churchill, Ltd., London), and Microscopic Histo- 

 chemistry by George Gomori (University of Chicago Press, U.S.A.). 



It was stated in a review in a Balkan journal, and correctly so, 

 that the first edition of this book gave no information on the tech- 

 niques used in eastern and south-eastern European countries. 

 The reason for this is the scarcity here of the medical and bio- 

 logical literature of those countries. I am not a linguist, but I have 

 painfully translated some hundreds of pages of French and Ger- 

 man literature to find some missing link for inclusion in this 

 present edition and, if any medical or biological laboratory workers 



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