( 1007 ) 
to the purpose. An experiment like the one, detailed in Table IL may 
even more strongly than the preceding one (Table I) create an 
impression, when we compare 5) and 6), that trypsin might be activated 
by chlorid of calcium. Im 6) the activation has undoubtedly been 
effected by the bacteria, which have developed themselves in the 
non-sterile water (+ pancreatic-juice); in 5) the greater activation 
might have been caused by the joint action of bacteria and CaCl, . 
And since in 5) the digestion was greater tban in 6) there were 
plausible reasons for concluding that chlorid of caleium had contributed 
to the activation of trypsinogen. Still, as my attention had been 
direeted to the possibility of a stimulating action of chlorid of calcium 
on trypsin, the difference in digestion between 5) and 6), when looked 
at from this point of view, might find an explanation in this sense. 
Further discussion of this experiment may be esteemed superfluous ; 
I thought it advisable to insert it here as an additional proof that 
we have fo be very careful about conclusions as to a contingent 
activating effeet of chlorid of calcium on trypsinogen. 
Whilst on the ground of the preceding observations it seemed not 
unlikely that chlorid of calcium might have a stimulating effect on 
trypsin itself, a closer investigation was begun now in order to test 
this supposition by means of experiments. For this purpose I made 
use of some commercial trypsin-preparations, viz. that of GRÜBLER 
and that of Merck. As the activity of the preparations in the labo- 
ratory was found to be very slight with regard to coagulated albumen 
| ordered fresh preparations a few times. I informed the firm of 
GRÜBLER as to this slight activity, upon which this firm sent me, 
as I was informed, a newly-made preparation. 
Yet the activity of this preparation was no greater than that of 
the preceding ones. That is to say as regards albumen, as regards 
fibrin the action of these preparations left nothing to be desired. 
3y making the concentrations of the trypsin-solutions (suspensions) 
considerably stronger than prescribed by the firm I could use these 
commercial preparations for my purpose. ‘The trypsin-solutions 
(suspensions) were prepared by means of soda-solutions. As the use 
of Na,CO, seemed liable to some objections, however, owing to the 
slight solubility of the CaCO,, resulting from CaCl, being added, 
I made use of very weak (as a rule 0.1 °/,) solutions of Na,CO,. 
That there was no objection to the use of a 0.1 °/, sol. of Na,CO, 
is seen from the following experiment, which for the rest served 
to investigate the stimulating effect of CaCl, on trypsin-action (Table III). 
For this experiment 1 gramme of trypsin-GRÜBLER was dissolved 
56* 
