( 1010 ) 
From the preceding experiment (Table IV A and B) we may 
conclude what foliows. Comparison between A 3—6 and A, and 
likewise between B 3—6 and B teaches that also in this experiment 
the intestinal mucous membrane extracts have had a favourable 
effect on the trypsin-action. From the result that the albumen- 
digestion in A3, 4, 5, and 6, and likewise in B 3, 4, 5, and 
6 differed little or nothing, that consequently the hoiled extracts 
of the intestinal mucous membrane were found to have the same 
favourable effect as the unboiled ones, we may conclude that in the 
trypsin-preparation used, no trypsimogen was present. The fact that. 
in spite of this the albumen-digestion in A 838—6 was found to be 
considerably greater than in A,, whilst this was also the case with : 
B3—6 and B, respectively, could in my opinion be explained only 
by assuming that in the extracts of the intestinal mucous membrane, 
in ether words, in the intestinal mucous membrane, a substance is 
found which can promote the trypsin-action, a substance which 
(contrary to the substance activating trypsinogen) could not be rendered 
inactive by being boiled. 
From the result that the trypsin used, was found to contain no 
trypsinogen, it also follows that the favourable effect of chlorid of 
calcium, observed in the preceding experiment (Table III) must be 
altributed to the heightened action of trypsin, occasioned by chlorid 
of calcium. The intensifying action of chlorid of calcium, as regards 
trypsin, likewise manifests itself, and that very obviously, in the last 
experiment (Table IV A and B). For in A, the albumen digestion 
is seen to be much greater than in A,. That in B, no digestion 
took place at all, must undoubtedly be attributed to a precipitate 
of CaFl, being formed here, which had sunk to the bottom of the 
test-bottle, and surrounded the Mett’s tubes, so that the trypsin-action 
could not manifest itself. Comparison between A 3—6 and A, shows, 
moreover, that the stimulating effect of the intestinal mucous membrane 
extract is a slighter one than that caused by chlorid of calcium, at 
least in the concentration used *). 
Further it may be concluded from A3 and 5 and B3 and 5 
(Table IV) that the substance deriving its origin from the intestinal 
mucous membrane, and promoting the trypsin-action, is in all proba- 
bility no calcium-salt. For it may be assumed that a calcium-salt, if 
it were present in the extracts used, would have been precipitated 
by NaFl as insoluble CaF l,. This last observation likewise holds good, 
1) An investigation as to the influence of the concentration of the chlorid of 
calcium-solution, and also as to the effect of some other soluble calcium-salts on 
trypsin, is in progess, but has not yet been completed. 
