BORIC ACID AND BORAX. 



151 



cause a profound disturbance in digestion, with a marked tendency to 

 decrease the amount of food digested and absorbed. Thus we find 

 that while the total calories administered during the after period are 

 almost exactly the same as the total calories of the preservative and 

 fore periods, the amount of solid matter left in the feces is enormously 

 increased, with a necessarily corresponding decrease in the percent- 

 age of absorption. To be more exact, the calories in the food in the 

 fore period are 3,365, in the preservative period 3,308, and the mean 

 calories for the two periods are 3,336, while the value of the calories 

 in the food in the after period is 3,356. 



It is evident that when a preservative of this kind is administered 

 over a long period of time its effect at first is not very marked. There 

 are no profound disturbances of digestion which could be noted from 

 any observable symptoms. There is no marked production either of 

 nausea, a feeling of discomfort in the region of the stomach, or con- 

 tinued headache, as' are sometimes produced when the same preserva- 

 tives are administered in large quantities. There is a tendency, on 

 the other hand, in the system to accomodate itself to the condition of 

 affairs which obtains. There is evident an increased excitation of the 

 glands supplying the digestive ferments, but in the case cited this 

 increased excitation is not quite commensurate with the restricting 

 influences upon the digestive processes. When, however, the stimulus 

 of the preservative is withdrawn there appears a decided tendency to 

 diminish the activity of the digestive processes and thus to increase 

 the amount of dry substances in the feces as a result of diminished 

 amounts of the nutrients absorbed. This theory at least is worth con- 

 sideration, as it agrees with the general principle of the tendency to 

 collapse on the withdrawal of long-continued stimulation, and also with 

 the recorded data obtained during this long period of experiment. 



TABLE XXII. Summary of weight and water content of feces, 



SERIES I SIX MEN. 

 [Figures given are averages per day.] 



series. 



