118 THE DIGESTIVE FLUIDS. 



artificially reduced to that minimum which is tenaciously retained 

 are no longer capable of secreting hydrochloric acid. The mech- 

 anism, however, by which the format ion of hydrochloric acid takes 

 place is, as has been stated, unknown. Ludwig formerly thought 

 that it resulted through electrolytic influences within the cells, and 

 that the acid then diffused out into the lumen of the glandular duct 

 before the alkaline elements of the cell could bring about its neutral- 

 ization. This, however, is improbable, and the view that is now 

 held by most observers is that expressed by Maly, according to 

 which the hydrochloric acid results from a mass-action on the part 

 of the carbonic acid of the blood upon the chlorides in the body of 

 cells, and is immediately eliminated to the outside, while the result- 

 ing bicarbonate is returned to the blood. We know that within the 

 cells carbon dioxide is present under great pressure. Schlierbeck 

 thus found that water which is introduced into the stomach of living 

 dogs after a variable length of time contains a certain amount of 

 carbon dioxide, and that its tension rises from 30 to 40 Hgmm. 

 while fasting, to 130 to 140 Hgmm. during the process of active 

 digestion. 



Of late, Liebermann has further suggested that lecithalbumin may 

 be present in the parietal cells in combination with sodium chloride, 

 and that hydrochloric acid may result from this through a mass- 

 action on the part of carbonic acid, which, in turn, is formed within 

 the cells as a result of an increase of their functional activity. 



Significance of the Hydrochloric Acid. The assumption that the 

 principal function of the hydrochloric acid consists in its pow r er to 

 render the pepsin of the gastric juice physiologically active, viz., 

 capable of bringing about the transformation of albumins into albu- 

 moses and peptones, has now been largely abandoned. We know 

 that life can go on in the entire absence of the stomach, as has been 

 proved not only by experiments on animals, but also by operations 

 which have been performed on the human being. A dog whose 

 stomach was almost entirely removed by Czerny in 1876, lived for 

 more than six years after the operation, when it was killed in Lud- 

 wig's laboratory ; and it is reported that the animal was normal in 

 every respect, and had increased in weight from 5850 grammes to 

 7000 grammes. It is thus manifest that while the hydrochloric acid 

 of the gastric juice no doubt aids in the process of albuminous di- 

 gestion, its presence to this end is not imperative, and the question 

 naturally suggests itself, whether the secretion of such large amounts 

 of acid does not serve another and perhaps more important purpose. 

 This purpose is now thought to be the prevention of putrefactive 

 changes in the contents of the stomach, and we find, as a matter of 

 fact, that albuminous material that has been removed from the 

 stomach at the height of digestion can be preserved for a long time 

 without undergoing decomposition. It has been noted, moreover, 

 that the gastric juice is also capable of arresting putrefactive proc- 

 esses when these have begun before the ingestion of such material. 



