DIGESTION. THE MOUTH. 397 



no yet known law. It may "be, and frequently is, as successful 

 as rational treatment, or sometimes even more so ; but whether 

 successful or unsuccessful, we can offer no scientific reason for 

 it. All that we can say is, that experience has proved incon- 

 testably that a particular kind of treatment was beneficial in a 

 multitude of instances, and that it will probably be beneficial 

 again. We hope soon to know more about the various remedies 

 that have been successfully employed ; and as we acquire this 

 knowledge, and come to be able to give a reason for their effects, 

 i.e. refer them to some great natural law, we shall transfer these 

 remedies from the group headed "empirical," and add them to 

 the group called "rational." Therapeutics will become a perfect 

 science when empiricism has thus without exception given 

 place to rationalism. 



Plan of the following chapters. In approaching the study 

 of the general therapeutics of the different systems of the 

 body, we will adopt the following plan suggested by the pre- 

 ceding considerations: (1) We shall give a brief sketch of 

 the physiological relations of the system. (2) We shall con- 

 sider fully the pharmacodynamics of the same, dealing 

 chiefly with the drugs examined in the previous parts of the work, 

 but referring frequently to non-medicinal measures, such as 

 food, air, exercise, and baths. (3) A rapid sketch will be given 

 of some of the pathological relations of the system, those being 

 selected which best serve to illustrate the action and uses of 

 remedies, i.e. disorders or derangements rather than diseases 

 of the parts. (4) A brief reference will be made to the evidence 

 of natural recovery in the particular system, and to the failure 

 of such attempts, i.e. the limits of treatment. (5) The rational 

 therapeutics of the system, founded on the previous four divi- 

 sions, will complete the account. 



CHAPTER II. 



DIGESTION. THE MOUTH. 



I. PHYSIOLOGICAL RELATIONS. 



THE process of digestion begins with the reception of food, 

 more or less prepared by cooking. During its brief stay in the 

 mouth, the food is triturated and mixed with mucus and saliva, 

 and its starchy constituents are partly converted into sugar. 



1. Food forms no part of the subject of the present work, 

 and it will be sufficient to remind the student that the chief 

 proximate principles of a proper diet are proteids, amyloids, fat, 



