2 Vines . — Tryptophane in Proteolysis. 
phane among the products of digestion of fibrin and of Witte- 
peptone. 
It is already known that the action of certain of these 
vegetable enzymes is ‘tryptic,’ since it has been ascertained 
that they cause the formation of leucin and tyrosin in proteo- 
lysis. This is the case with bromelin, papain, the enzyme 
of germinating seeds, and with the enzymes of Yeast and 
Bacteria. The products of digestion by the enzyme of the 
Fig ( cradein ) have not yet been sufficiently investigated 
from this point of view. 
The only attempts at quantitative estimation of the activity 
of the vegetable enzymes are those of Chittenden (3) regarding 
bromelin, and of Martin (4) regarding papain. The method 
employed by these observers was that of supplying a known 
weight of digestible proteid (albumin) and determining the 
weight of proteid remaining undigested at the close of the 
experiment. Whilst the results so obtained are of value, 
the method is open to the criticism that when HC1 or Na 2 C0 3 
is present in a digestive mixture, the solution of the proteid 
may be due in part to the action of the acid or of the alkali, 
and to that extent the numerical result would be vitiated. 
Nor does this method afford any evidence as to whether 
or not the proteid that has passed into solution is in the 
same stage of proteolysis in digestions which may have to 
be compared. In employing the tryptophane-test for this 
purpose, I have not had any close quantitative estimation 
in view. My object -has been to ascertain, under various 
conditions and with various enzymes, the time required to 
form tryptophane ; and to compare the intensity of the re- 
actions as indicated by the depth of colour. In this way some 
rough idea as to the relative activity of proteolysis has 
been obtained. It would be, I believe, possible to develop a 
quantitative method on the basis of the tryptophane-reaction, 
by ascertaining the volume of chlorine-water necessary 
to produce the same depth of colour in equal quantities 
of the various digested mixtures ; the coloured chlorine- 
compound in each being extracted by shaking with equal 
quantities of amyl-alcohol in which it is readily soluble. 
