Kiihne and Chittenden— Peptones. 231 
‘infusion obtained from the 88 grams of self-digested pancreas, after 
which the mixture was continued at 40° C. for six days. At the end 
of the first day nearly all of the fibrin had disappeared, although a 
considerable portion appeared to float on the surface of the fluid. 
When examined more closely, however, this residue proved to be 
extremely light, hollow, easily crushed and with a somewhat greasy 
feeling. A similar residue, the amount of which we did not deter- 
mine, remained at the end of six days aud consisted mainly of 
antialbumid with much tyrosin. 
Preparation of the antipeptone.—The solution resulting from the 
above digestion was made slightly acid with acetic acid, boiled, 
passed through a filtering bag, concentrated to 1 litre, and freed 
from a large amount of leucin and tyrosin by crystallization and fil- - 
tration. The resultant, brownish-looking syrup was treated with 
alcohol until peptones began to precipitate, and after the latter had 
been redissolved by boiling the solution, it was placed aside for 
erystallization. The filtrate, which now contained only a small 
amount of amido acids, was freed from alcohol by boiling, diluted 
with a saturated solution of ammonium sulphate, which had also 
served for washing out the mass of crystals on the filters, and then 
completely saturated with the ammonium salt in substance. After 
separating the slight precipitate so formed, in which some lencin and 
tyrosin was detected, the greater portion of the ammonium salt was 
removed from the filtrate by repeated concentration and crystalliza- 
tion, while the remainder was gotten rid of, as before, with barium 
hydroxide and barium carbonate. Since in this case, precipitation 
with phosphotungstic acid could not yet be employed, we attempted 
to purify the peptone as much as possible from other products of 
digestion (amido acids), first, as a barium compound by repeated 
precipitation and boiling with alcohol, after which the barium-pep- 
tone was exactly decomposed with sulphuric acid and the free pep- 
tone purified in a similar manner by repeated precipitation and extrac- 
tion with alcohol, once or twice in the presence of a little acetic acid. 
The peptone thus obtained, when dried at 105° C., weighed 120 grams. 
Assuming that albuminous bodies by complete typsin digestion, split 
up into 50 per cent. of products arising from the wholly decompos- 
able hemipeptone and 50 per cent. of antipeptone not further 
changed by typsin, then the amount obtained—120 grams—agrees 
with this so far as it is possible, with the unavoidable losses which 
the treatment of large quantities in this manner implies. The 388 
grams of dry albumin (300 grams of fibrin and 88 grams of self- 
