234 Kihne and Chittenden—Peptones. 
previous case; that is, a barium peptone compound was formed, puri- 
fied with aleohol and this exactly decomposed with sulphuric acid. 
In order to separate the free peptone, the solution was concentrated 
at a gentle heat with the addition of a little ammonia, precipitated 
and boiled with alcohol, the almost liquid’ precipitate dissolved in 
water, the solution acidified with acetic acid, concentrated again, pre- 
cipitated and extracted hot with alvohol, repeatedly washed and 
kneaded with ether, kept for a long time under ether and then slowly 
dissolved in as small an amount of cold water as possible. When 
filtered, a small residue of tyrosin appeared in the preparation. The 
new solution was concentrated at a gentle heat, precipitated again 
with alcohol, the peptone boiled and washed with alcohol, allowed 
to stand for some time with a large quantity of absolute alcohol, 
again treated with ether as before, and as it had now become friable, 
it was immediately dried in vacuo over sulphuric acid. On attempt- 
_ ing todry it at 100° C. the melting mass foamed so much that it had to 
be dried in the air. When this had been done with frequent stirring 
on the water bath for several days, the mass was finally dried com- 
pletely im vacuo, first at 100° C., then at 105° C. A few weeks of 
this drying were needed to bring the substance to a constant weight, 
and in order to prepare the various quantities for analysis they had 
to remain in vacuo over sulphuric acid and at 105° C. for some time. 
Probably in consequence of the thorough treatment with ether, the 
preparation when warmed gave much less odor than the former one, 
Composition of Antipeptone (D). 
I. 0°5061 gram substance gave 0°2875 gram H,O = 6°31 per cent. 
H and 0°7937 gram OO, = 42°76 per cent. C. 
II. 0:4449 gram substance gave 0°2527 gram H,O = 6°31 per cent. 
H and 0°7024 gram CO, = 43°05 per cent. C. 
III. 0°5010 gram substance gave 0'2870 gram H,O = 6°36 per cent. 
H and 0°7885 gram CO, = 42°91 per cent. C. 
IV. 0:4414 gram substance gave 56°0 c.c. N at 21°0° C. and 
759°2 mm. pressure = 14°91 per cent. N. 
V. 0°5870 gram substance gave 76:5 c.c. N at 216° C. and 
758'0 mm. pressure = 15°13 per cent. N. 
VI. 06930 gram substance gave 0°0694 gram ash = 10°01 per cent. 
VII. 05017 gram substance gave 00504 gram ash= 10:04 per cent. 
VIII. The ash from 05017 gram substance gave 0°0325 gram BaSO, 
=0'89 per cent. S calculated on the original substance. 
