Kiihne and Chittenden—Peptones. 237 
and long continued action. However this may be, the albumins of 
the pancreas naturally cannot be classified with the substances ordi- 
narily used in digestion experiments, such for example as fibrin, 
without further investigation, for although there may be substances 
in the gland cells like serum-albumin, globulin and myosin, there are 
also many bodies quite different from these, as, for example, the leu- 
coid precipitated by excess of acetic acid, zymogen and trypsinogen, 
all of which are decomposed by self-digestion and yield amido acids 
and peptones. So long as trypsin digestions are not ordinarily con- 
ducted with pure trypsin, it is of especial interest to find out the 
composition of the gland peptones, which, as a rule, have invariably 
been mixed in greater or less quantity with the antipeptones hitherto 
investigated. 
Preparation.—1,000 grams of dry pancreas were warmed at 40° C, 
for twelve hours with five litres of 0:1 per cent. salicylic acid and 
0:25 per cent. of thymol, filtered through muslin, the residue 
warmed another twelve hours with two litres of 0°25 per cent. 
sodium carbonate and 0°5 per cent. of thymol, again filtered and 
pressed, the two fluids united, brought up to an alkalinity of 0°25 
per cent. of sodium carbonate and then warmed at 40° C. for three 
days. 
After filtering through paper, the whole solution was slightly acidi- 
fied with acetic acid and then saturated with five kilos. of ammo- 
nium sulphate, by which means there was precipitated a little albu- 
' mose and all of the trypsin, the further treatment of which is of no 
interest here, while the gland peptone remained in solution. It is 
to be noticed in the separation of this peptone that it was treated 
exactly like preparation (C), excepting that the second purification 
with ether could be omitted. The preparation, after drying for some 
time, left a small residue of tyrosin when dissolved in cold water. It 
was therefore precipitated from this solution with alcohol, then freed 
from alcohol by boiling with water, dried directly over a water-bath 
and finally im vacuo at 106° C. until a constant weight was obtained. 
The analysis of the product is seen in the following table. 
Antipeptone (G). (Gland peptone.) 
This preparation was obtained from the preceding product by the 
following process; the solution of the peptone was acidified with 6 
per cent. of sulphuric acid, precipitated with a large excess of phos- 
photungstic acid, the precipitate carefully washed, then decomposed 
with barium hydroxide, the latter exactly removed with dilute sul- 
