34 THE SECRETIONS: 



to practical medicine, little is known with certainty in relation 

 to their true causes, and still less respecting the peculiar influ- 

 ences that morbid gastric juice exercises on chymification and 

 chylification. The question naturally suggests itself, whether 

 morbid changes in the gastric juice may not be the origin of 

 many of the diseases of early childhood. Such changes may 

 originate purely from internal causes (nervous influences,) or 

 from a complication of the above with external influences, 

 such as diet, &c. 



The only modifications respecting which we can speak with 

 any degree of certainty are the following : 1st, There may be a 

 considerable excess of free acid; 2dly, There may be a diminution 

 of free acid; and 3dly, The gastric juice may become posi- 

 tively alkaline. In all probability, with these there are associ- 

 ated other changes in the composition of the fluid, producing 

 an injurious effect on the process of digestion ; but on this sub- 

 ject we are unable to speak with certainty. 



The increased acidity of the gastric juice usually arises from 

 an excess of those acids which exist in it in a normal state, 

 namely, muriatic, acetic, and lactic acid. When there is a 

 tendency to the formation of an excess of acid in the gastric 

 juice, it appears to be developed from the food. Muriatic acid 

 is principally developed from animal food; acetic and lactic 

 acids from vegetable and especially saccharine food, such as acid 

 bread, beer, and wine ; and the fatty acids from an excessive use 

 of fatty matters. An excessive acidity of the gastric juice is 

 frequently observed in cases of gastritis serosa, and of scrofula 

 and rickets associated with disease of the spleen. In gout, po- 

 dagra, and nettlerash, the gastric juice contains, according to 

 Stark 1 , phosphoric and uric acids ; the presence of the latter 

 acid must however be regarded as very problematical. 



The cases in which the gastric juice exhibits a positively al- 

 kaline reaction are comparatively rare. This deviation from the 

 normal condition arises chiefly from the use of salted or putrid 

 food and drink containing basic salts, from prolonged fasting, 

 and especially from care and anxiety (Stark.) 



The experiments of Purkinje and Pappenheim show that 

 when the gastric juice is mixed with bile, its digestive powers 

 are diminished. 



1 Allgem. Pathologie, p. 848. 



