iv PREFACE TO THE THIRD EDITION. 



range and is designed to give to the student as thorough 

 training as is practicable in a laboratory course and includes 

 well nigh all the more important varieties of confinement, 

 anaesthesia, disinfection, sutures, bandaging, dressing and 

 other adjuncts to operative work. The chapter on trephin- 

 ing of the facial sinuses has been dealt with at much greater 

 length in the present edition in order to fully and clearly 

 describe the author's method of operating. 



The operation for the surgical relief of roaring in horses 

 has undergone a complete revolution since the publication 

 of our second edition in 1906 and the technic therefor which 

 we had begun to develop in 1905 and tentatively inserted 

 in the second edition has undergone phenomenally rapid 

 changes until now it would appear that the technic had 

 acquired a certain degree of permanency, though still too 

 new to expect it to remain unchanged. The introduction 

 of the ventricular burr by Dr. J. H. Blattenberg and various 

 suggestions in the details of technic by Prof. Hobday of 

 England and others has materially aided in bringing the 

 operation to its present state of reliability and caused the 

 operation introduced by us in 1905 to become accepted 

 throughout America and Europe to the exclusion of other 

 methods. We have accordingly omitted the chapter on 

 arytenectomy from this edition, as an obsolete operation 

 and have inserted an entirely new chapter upon the opera- 

 rion for roaring in which we have endeavored to bring the 

 technic thoroughly up to date. 



Generally but one method of operating is described, the 

 one chosen being that which in the author's experience has 

 proven the most valuable in actual practice, and no opera- 

 tion has been introduced purely for practice but each one 

 has been tested and known to have practical value. 



When two methods of operating are given, they are 

 inserted because each has definite points of superiority over 

 the other and one method may be specially applicable in a 



