PREFACE TO THE THIRD EDITION. 



Ix the present edition of this work, the general plan and arrange- 

 ment of the two former ones are retained. The improvements and 

 additions which have been introduced consist in the incorporation 

 into the text of certain new facts and discoveries, relating mainly 

 to details, which have made their appearance within the last three 

 years. Such are the experiments of the author with regard to the 

 secretion and properties of the parotid saliva in the human subject, 

 and the quantitative analysis of this fluid by Mr. Perkins; the 

 valuable observations of Prof. Austin Flint, Jr., on Stercorine, 

 Cholesterin, and the effects of permanent biliary fistula, and those 

 of Prof. Jeffries Wyman on Fissure of Hare-lip in the median 

 line, from arrest of development. Three new illustrations have 

 been introduced, one of which (Fig. 183) replaces a previous one. 

 The author is much indebted to his friend, Dr. Foster Swift, for 

 aid in carrying the work through the press. 



NEW YORK, January, 1864. 



(v) 



