THE ACID OF THE GASTRIC JUICE, 363 



These facts indicate that the formation of hydrochloric acid is a 

 process going on in the cell, that the acid is a cell secretion, and not a 

 diftusate from the blood plasma. 



Gamgees modification of Malys theory. Gamgee, 1 while retaining 

 the supposition that the hydrochloric acid is formed by the action of 

 the alkaline phosphates on the chlorides, removes the seat of action from 

 the blood to the parietal cells. He supposes that these cells possess a 

 peculiar selective absorption for the phosphates of sodium, both alkaline 

 and acid, and for chlorides, and that within the cell there occur the 

 same reactions between these substances as occur in vitro when they 

 coexist in solution. One of the products of the reaction will then be 

 hydrochloric acid, which, in virtue of its high power of diffusion, will 

 pass, as soon as formed, into the secretion of the gland. This supposition 

 is certainly a step in the right direction, in so far as it brings the seat 

 of action to the cell a much more probable place than the blood but, 

 on the other hand, it assumes a good deal, without overcoming many of 

 the objections to Maly's theory. Thus, selective absorption, of both 

 alkaline and acid phosphates (probably di- and mono-sodium phosphates) 

 is assumed. Unless these are also assumed to be absorbed in such pro- 

 portions that the reaction of the cell contents becomes acid, no formation 

 of hydrochloric acid will take place, for, under merely physical conditions, 

 no such formation can be demonstrated in vitro. 



Unless, again, the substances selectively absorbed are kept out of 

 action in some equally obscure manner by cell activity, there is no 

 reason why the secretion of acid should not be continuous ; and if absorp- 

 tion of phosphates and chlorides only begins at the commencement of 

 digestion, it is not easy to see how the traces of hydrochloric acid, 

 formed by such interactions, can keep pace with the demand then made 

 for hydrochloric acid. 



Lastly, there is no experimental evidence that there is any such 

 selective absorption of phosphates and chlorides by the parietal cells. 

 And if a purely physical theory is to be abandoned, and a specific functional 

 activity of the cell invoked, there remains no reason for adhering to 

 theories which have been evolved on a purely physical basis. 



It is easier, and more in accordance with our notions regarding the 

 secretion of other substances, to suppose that the hydrochloric acid 

 is formed by cell activity in some metabolic process, from the chlorides 

 and organic matters at its disposal. There are an infinite variety of 

 such processes capable of taking place, under the varying conditions of 

 cell life. It is true we do not know the details of these, nor why such 

 processes take place under certain given conditions ; nevertheless we 

 see the end-results, and there is no reason why hydrochloric acid should 

 not also be the end-product of such a cell metabolism rather than the 

 product of a kind of specialised diffusion. 2 



1 " Physiological Chemistry," 1893, vol. ii. p. 113. 



2 Hammarsten, " Lehrbuch der physiol. Chem.," Wiesbaden, 1895, Aufl. 3, S. 242. 

 See also Heidenhain, Hermann's Handbuch," Bd. v. (1), S. 151. One such possible process 

 is the formation in the cell of an organic acid which does not diffuse away, but is retained 

 in the cell and' exercises a continuous action on the chlorides, forming hydrochloric acid 

 which the cell actively excretes. Another possibility would be the formation during 

 rest of an organic chlorine-containing substance, while the base combined with carbonic 

 acid passed into the blood, and the subsequent breaking up during activity of this 

 chlorine-compound yielding hydrochloric acid. There are indeed many courses which such 

 a cell-metabolism might take yielding hydrochloric acid as an end-result. See also Bunge, 

 ''Lehrbuch der physiol. Chemie," Leipzig, 1894, Aufl. 3, S. 149. 



