THE WORK OF THE DIGESTIVE GLANDS. 



obtain a method uniform with those applied to the other ferments. As 

 matters now stand, the method we are compelled to use demands the 

 continuous attention of the experimenter, and is therefore very tiouble- 

 some where numerous estimations have to be made. But this is un- 

 avoidable when the properties of the juice have to be followed from 

 hour to hour, or even at still shorter intervals. To this it must be 

 added that the results of the method are not always equally reliable. 

 The law of Schiitz and Borrisow was, however, confirmed here also. 

 Naturally our experiments deal in general only with comparisons of 

 ferment activity, and our deductions concerning "quantities" and "total 

 amounts " of ferment must therefore be accepted conditionally. In 



FIG. ;">. Digestive power of hourly portions of -astric juice 

 aftfi- administration of 400 ^nns. of tlrsh. (Expt-i-i- 

 inrnts of IT) tli and 10th May 1S'.5.) 



many instances however, perhaps with gastric juice in all, we ma}' 

 correctly speak of a quantitative determination of the ferment, since in 

 the case of this juice the digestive power always runs parallel with its 

 content of organic mateiial. 



A few words concerning how we estimated the alkalinity of 

 pancreatic juice. The solid residue of a measured quantity of juice 

 was incinerated over a weak fire, and the ?alts, dissolved in water, 

 and titrated. The result was reckoned in terms of Na.,CO 3 and ex- 

 pressed in percentages of the original quantity of juice. 



The experiments, from the description of which I broke oft' in order 

 to give these necessary explanations of methods, will now be given in 

 two pairs : the one pair dealing with the gastric glands, the other with 

 the pancreas. They furnish evidence showing that the properties of the 

 digestive juices vary during the progress of secretion according to the 

 same laws which we have learned to hold good for their variations in 

 hourly quantlt;/. 



