1881.] and Proteolytic Activity of Pancreatic Extracts. 149 



we can further conceive that in action it will discharge this energy 

 gradually, and also at a rate which is continually diminishing. Such 

 a conception will, I think, enable us to understand some features in the 

 action of diastase and trypsin which are otherwise difficult to explain. 



In regard to the action of pancreatic extract on starch mucilage, the 

 rule of inverse proportion between quantity and time was found to hold 

 good within considerable limits, as the following experiments show : — 



Table I. 



Experiments showing the inverse proportion between quantity and 

 time in the action of pancreatic extract or starch mucilage. The 

 quantity of the standard mucilage acted on in each experiment was 

 10 cub. centims. diluted with water up to 100 cub. centims. Tem- 

 perature 15° C. The "calculated" time in the third column was 

 obtained by taking the middle observation to each set as a standard of 

 comparison. 





Quantity of pancreatic 

 extract employed. 



Time in which the achromic point 

 was reached. 



Found. 



Calculated. 



r 



- 02 cub. centim. 



34 minutes 



36 minutes 



-04 



18 „ 



18 „ 



i \ 



-08 



9 „ 



9 „ 



o-io 



7 „ 



' 5 JJ 



L 



-20 



3 „ 



^2 >> 





0-4 



4! „ 



5 „ 



,,...{ 



0-2 



10 „ 



10 „ 





-05 



40 „ 



40 „ 



In both sets of observations the inverse time-rate is seen to come 

 out true with almost mathematical accuracy. 



"When, however, a relatively small quantity of pancreatic extract 

 was employed, and the time required to reach the achromic point 

 was, in consequence, considerably lengthened, it was found that the 

 advent of the achromic point was postponed beyond the term indi- 

 cated by the rule. If the period occupied in reaching the achromic 

 point fell within the compass of an hour, and the temperature was 

 low, as in the observation just recorded, the inverse time-rate came 

 out true, but when the period of action extended to several hours and 

 the temperature stood higher, the departure from the rule was un- 

 doubted. The annexed table gives the results of an experiment made 

 with a view of testing this point. 



