156 Prof. B. Moore. On Free Hydrochloric Acid [Feb. 28, 
hypothesis, and continued observations of the acid-secreting function under 
varying conditions (such as early in the disease, soon after removal of growth, 
repeated observations at varying intervals after operation, and observations 
early in recurrence), must teach us the relationships of the variations in acid 
production to the appearance of new growth. 
It may be allowable, however, in concluding this paper, to throw out a few 
suggestions, as to the probable cause of the change in the secretion of the 
acid, which are capable of forming the basis for additional investigation. 
(a) The diminution in acid secretion may be due to atrophy or loss of 
function of the oxyntic or acid-secreting cells. 
A diminution in the percentage of hydrochloric acid has been observed in 
old and senile individuals, the average amount of free hydrochloric acid being, 
it is said, only shghtly over 0-1 per cent. instead of 0-2 per cent. This 
diminution is, of course, very much less than in the malignant cases, but it 
shows that there is a tendency to diminution of acid-secreting power in the 
cells with advancing age, and hence suggests that in carcinomatous cases 
there may be an abnormal diminution in this power of the cells to secrete 
acid. 
Accordingly an investigation of the histology of the gastric mucous 
membrane is suggested in cases of malignant disease, especially where the 
erowth has not invaded the stomach. Such investigation would have to be 
done most carefully, because long continued perversion of function might lead 
to atrophy as a secondary and not a primary effect. Also post-mortem work 
alone might easily lead to wrong results, because the gastric cells must share in 
the general wasting due to the growth. The experiments indicated might hence 
best be taken up in the case of animals suffering from malignant disease. 
(6) The diminished acid secretion may arise from changes in the circulating 
medium, which do not cause atrophy of the cells, but which alter the activities 
of the cell so that it can no longer form acid ; or the materials for the formation 
of the acid may be Jacking in the material supplied to the cell. 
First, toxic substances may be formed at the seat of growth which circulate 
to the oxyntic cell and pervert its functions, alter its permeabilities for 
different ions, or in some manner destroy its normal power of secreting the 
acid. In this case if the growth were early removed, before the oxyntic cells 
had been long thrown out of normal action, then one would expect a return 
to the normal condition of affairs. Accordingly, we here require systematic 
and careful investigation of the effects of early removal of the growth upon 
the acid secretion 
Secondly, the action may not be a toxic one in the above sense, but may be 
