THE ACID OF THE GASTRIC JUICE. 361 



juice was an unsolvable riddle. But when Thomsen had shown that 

 the weakest acid is in some measure capable of displacing the strongest 

 from its salts, and Maly that by a simple process of diffusion this strong 

 acid may be afterwards separated, the subject assumed a different aspect. 

 It was no longer necessary for the cell to be endowed with some force 

 of sufficient intensity, to directly break up such stable substances as the 

 alkaline chlorides. All that was necessary was that the cell should be 

 able from the organic material at its disposal to form an organic acid, 

 and afterwards to rapidly excrete the small fraction of hydrochloric 

 acid formed by the interaction between this organic acid and the neutral 

 chlorides, so that a fresh quantity of hydrochloric acid may be formed 

 by the mass action of the remainder of the organic acid on the remainder 

 of the chlorides. The organic salts so formed can then decompose by 

 cell activity into organic acid and base again, and the base be returned to 

 the blood stream. Since gastric juice is not accompanied by an organic 

 acid, this must be retained in the cell and induce a continuous cyclic 

 change. It is thus possible, with the aid of the new facts of physical 

 chemistry, to see that the process of secretion of hydrochloric acid can 

 be reduced to the same level as that of the secretion of any organic 

 material. 



This, however, is but a small portion of the entire problem. As Bunge 

 says: "In the appearance of the free hydrochloric acid lies nothing puzzling. 

 Puzzling only is the power of the epithelial cell to send the hydrochloric acid 

 freed from the sodium chloride streaming always in one direction towards the 

 lumen of the gland, and the sodium carbonate l simultaneously formed always 

 back in the opposite direction towards the lymph and blood channels. But 

 such a puzzle we meet everywhere in the living tissue. Every cell possesses 

 the power to dispose of material in a suitable manner, attracting or repelling 

 it and sending it streaming in different directions." J 



Malys theory. Maly has attempted to build on a purely physical 

 basis a theory of the formation of hydrochloric acid from the chlorides of 

 the blood, of which the following are the outlines : 3 



l>There are no theoretically alkaline salts in the blood. Blood 

 plasma owes its alkalinity to two theoretically acid salts, di-sodic 

 phosphate (Na 2 HP0 4 ), and sodium bicarbonate (NaHC0 3 ); besides 

 these two acid salts plasma contains excess of carbonic acid. 



2. Disodic phosphate in presence of calcium chloride forms some 

 free hydrochloric acid, thus: 3CaCl 9 +2Na 2 HP0 4 =Ca 3 (P0 4 ) 2 +4NaCl+ 

 2HC1. 4 



Chiefly from the facts above stated, Maly supposes that by the 

 interaction of these theoretically acid salts of the plasma, on the chlorides 

 present with them in solution, traces of hydrochloric acid are formed ; 

 these traces of hydrochloric acid are rapidly removed, on account of the 

 high diffusibility of hydrochloric acid, 5 by the gland-cells which act as a 



1 Bunge is considering the hydrochloric acid as set free by the action of carbonic acid. 



2 Somewhat freely translated from Bunge, " Lehrbuch der physiol. Chemie," Leipzig, 

 1894, Ann. 3, S. 148. 



3 Abstracted, from Maly, Hermann's "Handbuch," Bd. v. (2), S. 66. 



4 R. Pribram, Jahresb. u. d. Fortschr. d. Thier-Chem., Wiesbaden, 1871, Bd. i. S. 107 ; 

 Gerlach, ibid., 1873, Bd. iii. S. 109. 



5 Graham has shown that the free acids diffuse more rapidly than their salts ; HC1 

 diffusing thirty-four times as rapidly as NaCl. Graham was also the first to show that, by 

 diffusion of acid potassium sulphate, sulphuric acid was obtained in the dialysate, while 

 normal sulphate remained behind. 



