XVI PREFACE TO THE FOURTH EDITION. 



stant agreement with him ; since it is impossible that they should all 

 survey the subject from the same point of view." 



In conformity with a desire frequently expressed, both by critics and 

 readers, a large number of references have been introduced; and to 

 this addition, no small portion of the augmented bulk of the volume is 

 due. Here, as in his companion-work, the Author has felt himself com- 

 pelled, by want of space, " to limit his references, for the most part, to 

 those new facts and doctrines, which cannot yet be said to have become 

 part of the common stock of Physiological Science." The special In- 

 dex of " Authors referred to," will be found, he hopes, of service to 

 those who wish to know the views of the original writers quoted, upon 

 any particular topic. To the knowledge of many of these, he has been 

 led by the excellent " Handbook of Physiology" of Messrs Kirkes and 

 Paget, to which he gladly expresses his obligations in this particular. 

 He has himself consulted the originals, however, in all cases in which 

 he could gain access to them. 



In conclusion, the Author would repeat the remarks with which he 

 brought to a close the Preface to the first Edition (1842); u that in a 

 work involving many details, it is not to be expected that no error 

 should have crept in ; but that he has endeavored to secure correctness, 

 by relying only upon such authorities as appeared to him competent, 

 and by comparing their statements with such general principles as he 

 considers well established. For the truth of those principles, he holds 

 'himself responsible ; for the correctness of the details, he must appeal 

 to those from whom they are derived, and to whom he has generally re- 

 ferred. He hopes that he will not be found unwilling to modify either, 

 when they have been proved to be erroneous ; nor indisposed to profit 

 by criticism, when administered in a friendly spirit." 



UNIVERSITY HALL, November, 1852. 



