CHAP. II. The Stomach. 



1. THE object of investigating the function of this 

 viscus is to understand by what agents, and according to what laws 

 its purposes are accomplished. The most familiar and obvious use 

 of the stomach is the conversion of food into chyme. 



2. We are taught by our doctrines of causation, that every 

 change is produced by something added, or by something taken 

 away; accordingly an investigation, for the purpose of ascertaining 

 in what the above change consists, must be of the analytical kind. 



3. There is no such thing as a perfect or complete analysis. 

 To follow distantly the design of a perfect analysis in the present 

 instance would require that we should be so far informed of the 

 constituents of food, as to be enabled, by a comparison of food with 

 chyme, to say what the former has lost or what acquired by its con- 

 version into the latter. So perfect a knowledge is hopeless: we 

 have not even ascertained the relation of the constituents of food 

 with each other, so as to be enabled to say, how much in a conver- 

 sion is to be attributed to a change in the combination of its own 

 constituents, and how much to foreign ones. 



4. A few of the chymical differences might be enumerated : is 

 is then to be asked, what are the properties, or where are the pro- 

 perties which produced these changes, seeing that nothing like a 

 similar conversion will result from an imitative employment of the 

 same alleged agents? Let us, however, make a more precise indica- 

 tion upon this matter: he who profits by it must be a shrewd 

 inquirer. 



5. The relation subsisting between food and the function of 

 the stomach is to be considered (conformably with the general 

 division before expressed). 



1st, According to the mechanical relation subsisting between 

 food and the structure of the stomach. 



2nd, According to the relations between the chymical consti- 

 tuents of food and those supplied by the stomach. 



3rd, According to the relations between the vital properties of 

 the stomach and the properties of the same kind in food: thus far 

 they may be considered separately. They are also to be considered 

 reciprocally, that is, as the stomach acts upon food, and the con- 



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