VI PREFACE. 



this manner attended my labors may prove an encouragement to others 

 to devote themselves with better results to a similar task. 



To physicians I would earnestly address myself, in the hope of ob- 

 taining their continued aid and hearty patronage for every such attempt. 

 I would ask them why it is that we never hear of empiricism in Natural 

 Philosophy, Engineering, Astronomy ? Is it not because the principles 

 upon which those subjects rest have ceased to be speculative, and are 

 restricted to the demonstrative, the experimental, the practical? In 

 Philosophy, sects only arise while principles are uncertain ; in Medicine, 

 the quack only exists because there is a doubt. And considering the 

 condition to which the medical profession in our times has come, consid- 

 ering its decline in social estimation, and its shortcomings even in its 

 own judgment is it not the duty of every physician to inquire into the 

 causes of such a state ? 



If a watch is to be mended, or a steam-engine repaired, do we not ap- 

 ply the principles of common sense to the case ? Who ever heard of sects 

 among watchmakers, or quacks among engineers ? If we will only apply 

 ourselves in a right spirit to its study, there is nothing more mysterious 

 or incomprehensible in a living organism than there is in such mechanical 

 contrivances. There is nothing in the structure of man which the intel- 

 lect of man can not understand. It is this, indeed, which constitutes his 

 chief glory, and makes him a worthy representative of the wisdom and 

 power of his Creator. 



As in any mechanical contrivance, so in ourselves, imperfections and 

 disarrangements can only be repaired by a knowledge of the construction 

 of the parts, and their manner of working. The practice of Medicine 

 must rest on an exact Anatomy and a sound Physiology. As soon as 

 it is brought to this, empiricism will disappear of itself; it will need no 

 legal enactments, no ethical codes for its destruction. And for this rea- 

 son, if there were no others, it is the bounden duty of every physician to 

 encourage to the utmost within his own sphere of influence every attempt 

 to realize such a state of things. The encouragement which has been 

 given to this book I regard as a token that these principles are profound- 

 ly recognized by the medical profession of our country. 



To students of Medicine I may be permitted, on this occasion, to say 

 a few words. It was chiefly with the hope of influencing them, and 

 guiding them into the paths of scientific Physiology, that I was first in- 

 duced to write this book. I would impress on them the importance of 

 cultivating habits of thought arising from the exact and practical sci- 

 ences. A great revolution is impending over the profession to which 

 they have devoted themselves. If they design to take a leading posi- 

 tion, not merely following it as an industrial pursuit, but regarding it as 

 one of the most dignified and noble of human occupations, they must 



