249 Kihne and Chittenden—Peptones. 
A few observations on the taste of peptones are of interest. While 
the genuine albumins and the albumose bodies excite practically no 
sense of taste, the less so the purer they are, it appears as if peptones 
belong to the most offensively tasting bodies. In order to see what 
an important change the taste of an albuminous body undergoes on 
digestion, and at the same time what the taste of peptones is, warm 
50 ¢.c. of fresh milk to 40° C. and then add to it a small fragment of 
soluble trypsin (prepared from ox pancreas), which excites no taste of 
itself. The milk at first coagulates, tnen regains its former appearance 
by solution of the coagulum, but tastes no better than gall. Never- 
theless we believe that the especially objectionable taste proceeds not 
from peptones, but from certain compounds heretofore only acci- 
dentally separated from them. For, among our preparations, which 
as a whole tasted something like roast meat, as if burnt, but above all 
nauseatingly bitter and astringent even in a 2 per cent. solution, we 
found one that in a 10 per cent. solution was free from this dis- 
agreeable peculiarity and had a pleasant, sweet taste like meat. 
It is to be noticed that this was the preparation of antipeptone (F) 
which had not been purified by phosphotungstic acid. Only by 
taking a large swallow was there noticed a not unpleasant taste, 
peculiar to certain cheeses after becoming alkaline, 
The most important property for the separation and treatment of 
peptones is for the present, the lack of precipitation by a great 
number of reagents, which precipitate more or less perfectly albumins 
and albumose bodies, especially sodium chloride, either alone, or with 
the’addition of acid. We have repeatedly confirmed the observations 
made by Wenz that even sodium chloride and acetic acid, sodium 
chloride and nitric acid or metaphosphoric acid do not completely 
precipitate the albumose bodies. In whatever proportion these addi- 
tions may be made, there always remains at the end a solution which 
gives with alcohol a precipitate of salt, in which albumose is still to 
be found, or from which albumose may be separated by dialysing and 
concentrating, according to the method already used. The only per- 
fect precipitant of these substances is ammonium sulphate. It is how- 
ever an error to attribute to this salt the same action on peptones. 
Wherever peptones occur, they will always be found in the filtrate 
from a solution saturated with ammonium sulphate, and we must 
conclude from some opposed statements that in the experiments on 
which they are based, albumose bodies instead of peptones were pres- 
ent, since we are certain that by means of our new method, it can be 
generally shown what an unexpected difference exists between the ap- 
