Xll INTRODUCTORY RREFACE. 



Neither offer insuperable difficulties, and, given the faculty for 

 operating, determination and patience enough to attend to the neces- 

 sary details, together with certain opportunities, there is no reason why 

 any qualified practitioner who is so minded should not attempt and 

 achieve successful results in both. 



The opinions gi\en in this little volume are based principally upon 

 the results of more than roo cases given in detail (and illustrated as far 

 as possible) in the Appendix. These are taken consecutively, not 

 merely selected, and the mistakes as well as the successes are recorded, 

 as a reader must gain much more benefit from studying the difficulties 

 which others have met with than from a mere perusal of a list in which 

 only the successes are recorded. For their previously published 

 statistics and deductions on one or both operations the names of 

 Charlier, Colin, and Cadiot in France, Frohner, Moller, and Ostermann 

 in Germany, liang in Denmark, Degive and Hendrick.\ in Belgium, 

 and Farmer Miles in England and America, must always stand 

 pjre eminent. 



My thanks are due to Professor !M'Fadyean for assistance in reading 

 the proofs, to my partner, iMr F. H. Ridler, INLR.C.V.S., and to those 

 gentlemen, mentioned in the text, wlio have kindly heli)ed me in many 

 ways, especially in regard to the illustrations. I have also lo acknow- 

 ledge the courtes)- of Messrs Arnold & .Sons in lending the woodcuts 

 of various instruments. 



F. H 



Ken.siki;ton, London, \V. 



