DIGESTION. LECT V. 



LECTURE V. 



DIGESTION. 



ARGUMENT, ^Digest ion : Its final object ; changes effected by it. 



Aliments are divisible into three classes. 



Class 1. Azotised substances; albumine, fibrine, and caseine. Mulder's 

 proteine theory ; digestion of azotised substances.; gastric juice; move- 

 ments of the stomach. 



Class 2. Amylaceous substances; starch, sugar, and gum. Digestion 

 and conversion of starch into dextrine and sugar, and ultimately into 

 lactic acid. Diabetes. 



Class 3., Fatty substances; fat and oil.-*-Qrigin of fat in herbivora; 

 division and liquefaction of fats in the stomach; use of the alkali of 

 the bile and pancreatic juice; formation of an emulsion which is ab- 

 sorbed ; agency of fat in the formation of cells. 



Gases i.fthe stomach and intestines. 



Inorganic substances found in the organism* 



Aliments. THE existence and preservation of an animal 

 are dependent on the continual introduction into his body 

 of certain substances, called aliments. These, which are 

 usually solids, undergo in the digestive apparatus a series 

 of modifications, by means of which they are resolved into 

 feecal matters which are rejected, and other matters which 

 mix with, and eventually become converted into, blood. 



Digestion. The ultimate object of digestion is the pre- 

 servation of the integrity of the organism, by restoring to 

 the blood the immediate principles which it is constantly 

 losing during the act of nutrition. Reasoning leads us to 

 suppose, that all parts of the organism, undergo transforma- 



