1899-1900.] Dr J. S. M £ Kendrick on Enzymes in Tissues. 71 
again a fluid which dissolved pieces of fibrin in the course of the 
same day. The digestion was found to go on, not only at 38° C., 
but even in an ordinary atmosphere. This experiment proved 
that Briicke had at least found pepsin to be present in the juice 
of flesh. This flesh was mostly muscle, but it must have 
consisted as well of fat, arteries, veins, nerves, etc. 
Although Briicke thus obtained pepsin from a large piece of 
flesh, and references are made to the effect that in muscle as well 
as in most other tissues there is a diastatic enzyme of the nature 
of ptyalin or amylopsin, no one, so far as I can ascertain, has 
methodically taken up each tissue separately and made a 
glycerine extract of it, to ascertain whether any particular enzyme, 
or enzymes, exist in the different tissues. 
Description op Method Adopted in this Research. 
In consideration of the fact that Yon Wittich’s method of 
making glycerine extracts of tissues dissolved in most cases, at 
least, the enzymes which were present in the tissues, I adopted 
his method with slight modification. My object was not to 
determine the amount of the enzyme in the tissue, but to see if 
it were actually present. Otherwise, the task would have been 
an exceedingly difficult and laborious one, as various methods of 
extraction would have necessarily had to be followed in order 
to obtain the enzyme in its purest form, when it might be 
expected to show its greatest activity. 
All tissues were subjected to the same process. They were 
all fresh, except in the case of those obtained from the post- 
mortem room. The tissues (normal and pathological) were 
macerated and put in alcohol before any putrefaction or other 
change could occur. The only tissues in which putrefaction 
might have occurred were post-mortem tissues. The greatest 
care was taken in thoroughly cleaning the vessels into which 
the tissues were placed, so as to get rid of extraneous germs. 
The tissues were minced in a mincing machine, and afterwards 
pounded in a mortar with powdered glass, until they were in a 
fine state of division. They were immersed in absolute alcohol for 
twenty-four hours. The alcohol was then allowed to evaporate at 
