bo 
ov) 
bo 
Kiihne and Chittenden—Peptones. 
digested material from the pancreas) would have had to yield 194 
grams of antipeptone if there were no loss. The loss, however, of 
74 grams noticed in our experiment is sufficiently expiained by the 
noticeable solubility of peptone in the water contained in alcohol, 
and by the conversion of a portion of the peptone into antialbumid. 
Behavior of the antipeptone.—This peptone was still more difficult 
to dry than the amphopeptone formed by pepsin digestion, and it 
could only be accomplished after the removal of all alcohol by 
thorough boiling with water. As the solution became very concen- 
trated on the water-bath, hydrogen sulphide, as shown by reaction 
with lead acetate, was given off together with a strong odor of valeri- 
anic acid, which was also evolved quite noticeably at 105° C. In 
order to obtain a constant weight it was necessary to dry the mass 
at 10> 'C; | 
The analysis of the product is shown in the accompanying table. 
Antipeptone (D). 
The behavior of the preceding preparation while being dried, nat- 
urally suggested the suspicion that the substance was either decom- 
posable at 100° C. or less in the air, or else that it contained some 
decomposable admixture. We therefore attempted a further parifi- 
cation of antipeptone and at the same time a more cautious method 
of drying. 
For this purpose another preparation of antipeptone was made in 
the following manner. 
230 grams of commercial dry pancreas, somewhat less active than 
that employed in the preceding preparation, were warmed at 40° C. 
for three hours with 1200 ¢. ¢ of 0:1 per cent. salicylic acid, after 
which the mixture was neutralized with sodium carbonate and to it 
was added directly 1920 grams of boiled, moist fibrin, 82 grams of 
dry sodium carbonate and 32 grams of thymol. This mixture was 
warmed at 40° C. for seven days, at the end of which time the residue 
of the pancreas, the antialbumid prodused, and considerable sepa- 
rated tyrosin, formed a noticeable sediment, which was filtered off 
and pressed, after the residue had been thoroughly washed with 
water warmed at 40° C. The filtrate was made slightly acid, heated 
to boiling, and as this produced only aslight precipitate it was imme- 
diately concentrated to about three litres. On cooling, an abundant 
slate-colored precipitate separated, composed almost entirely of tyro- 
sin. After removing this by filtration, the solution was saturated — 
with ammonium sulphate and the resultant filtrate treated as in the 
