230 Kahne and Chittenden— Peptones. 
as gland peptone, being derived exclusively from the self-digestion of 
the albuminous bodies of the gland substance, without any addition 
of fibrin or other albumin. 
How superior the action of trypsin is to that of pepsin, is seen not 
alone in the total decomposition of hemipeptone which is accom- 
plished only by the former, but also in the incomparably more rapid 
and perfect change of albumose to peptone. Hence the particu- 
larly troublesome and tedious treatment of antipeptone with ammo- 
nium sulphate may well seem superfluous when there is no albu- 
mose present. We must however be perfectly sure, by a pre- 
liminary test with that salt, that albumose is absent and its use is 
unavoidable where impure trypsin is employed in large quantities; 
that is, where an infusion of the pancreatic gland or the so-called arti- 
ficial pancreatic juice is used. From the latter, ammonium sulphate 
" precipitates a mixture which contains besides unaltered, highly active 
trypsin, whose isolation we propose later to study in this way, vari- 
ous other bodies, such as albumose, whose removal is necessary in 
the preparation of pure peptone. 
Antipeptone (C). 
Preparation of the pancreatic juice.—100 grams of dried ox pan- 
creas, purified with alcohol and ether, were warmed at 40° C. with 
500 ¢. ¢. of 0-1 per cent. salicylic acid for 12 hours, and filtered 
through muslin. The residue was then mixed with 500 c¢. c. of 0°25 
per cent. sodium carbonate, a little thymol added and the mixture 
again warmed at 40° C. for 12 hougs. The acid solution, after it had 
been neutralized, was brought to the same degree of alkalinity with — 
sodium carbonate, a little thymol added and also warmed at 40° C. 
for the same length of time. After filtering and pressing the residue 
of tissue, both filtrates were united. The weight of the undissolved 
residue, dried at 100° C., amounted as usual to 12 grams. Thus the 
nuclei of the cells, the collagen and the portion of elastin undigested 
under these conditions, is equal to 12 per cent. of the dry pancreas, 
freed from fat. 
Digestion of the fibrin.—300 grams of dry fibrin, purified by wash. 
ing and boiling with water, then with alcohol ee finally by extrac- 
tion with ether were softened with boiling water (when the weight 
amounted to 970 grams after squeezing with the hands), then 
warmed at 40° C. with 3 litres of 0°25 per cent. sodium carbonate 
containing 0°5 per cent. of thymol. To this was added the whole 
