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Outlines of Human Physiology, by Herbert Mayo, 

 Surgeon, 8^c. 8fC. London, 1827. 



Under this title, Mr. Mayo has published a system of 

 Physiology, distinguished no less by the clearness and per- 

 spicuity of its style, than by the sound and judicious views 

 of the human economy which it presents. Accustomed to 

 deliver lectures on Anatomy and Physiology, Mr. Mayo, 

 has learnt to state, at once lucidly and concisely, the body of 

 knowledge which has been long accumulated ; and the ad- 

 vantage which he possesses as a practical physiologist, en- 

 ables him to digest no less ably the facts included in more 

 recent discoveries, to which he has himself contributed. 



The different parts of the subject are treated in the fol- 

 lowing order : — The properties of the blood ; the nature of 

 muscular action ; the forces which circulate the blood ; the 

 phenomena of the pulmonary circulation ; and the use of the 

 Bow of arterial blood through the body. 



Digestion is next considered ; — the production of chyle ; 

 the elimination of the refuse matter: the former subject 

 leading to the history of the lacteal and lymphatic vessels ; 

 the latter to a description of the kidneys, and of the skin, 

 taken as excretory organs. 



The functions of the brain and nerves, of the organs of 

 sense, and voluntary motion, are described afterwards. 



The volume closes with a description of the function of 

 generation, and of the phenomena attending the growth and 

 reparation of parts. 



The account of the circulation of the blood is, perhaps, 

 the cleverest part of the work, considering the great diver- 

 sity of interesting questions which it essentially involves. 



Upon the nature of the irritability of the heart, Mr. 

 Mayo remarks : *' the alternate action and relaxation of the 

 muscular fibres of the heart appear not, like similar phe- 

 nomena in voluntary muscles, to depend upon a series of 

 impressions transmitted from the brain or spinal chord. If 

 the heart be taken from the body of an animal immediately 

 after death,— if the blood be carefully washed from its in- 

 ternal surface, — if, at the transverse furrow, the auricles be 

 separated from the ventricles by a clean incision, the alter- 

 nate states of action and relaxation continue to succeed each 

 other in each part as before. For the brief period during 

 which it is reasonable to suppose that the heart retains its 

 perfect organization, no stimulus seems required to excite it 



