246 Kiihne and Chittenden—Peptones. 
Finally, not to overlook the most striking reaction of peptones, 
we mention further the brilliant so-called biuret reaction which is to 
be seen, if possible, still more intense in the purer peptones, what- 
ever their origin, than in those formerly used. 
Composition of the Peptones. 
For the sake of comparison we present in the following table the - 
percentage composition of the various samples of peptones, calculated 
on the ash-free substance. The ash found, consisting in every case 
of calcium, a little sodium, potassium, traces of barium and iron, car- 
bonic acid, phosphoric acid and sulphuric acid, is placed at the 
foot of the columns. 
Ampho- (pepsin) peptone from || Anti- (trypsin) peptone, 
A. B. | b. C. D. E. HS G. H. 
Prepared from fibrin. Glandpeptone. 
Certain a ae pepsin|| — 7 = 3 Ee = 
: an | 3 
‘ing mucin- SRAM niaGa: ae Purified al brane Purified with 
eptone. i more wi B- osphotungstie 
me avid: ether. | Photungs- y Pacid. = 
tic acid. | 
| 47°30} 47°68 46:59 | 4445] 42°96 44-47 
44:53 48°75 48°47 
649 721 7:02 6:69 ot 7:26 7-15 
2 
I 
ow 
—T 
i=) 
ioe) 
C 
H 
N | 16°73 16°26 16°86 | 1683. 16°68 18°28 | 17°06 | 17°80 17°94 
S | Ou2 | Ost By | (ei eee 0°67 | 050| 031 | O57 
©) 
| 31:53 HO) res We 28°41 | Pa Deel 
} 
Ash iil yuS 224) W216 M6254 
10°02 3°67 | 5:54] 193 2°07 
The nature of the substance, which at present affords but little 
proof that we have to deal with a simple body and not a mix- 
ture of chemical bodies, places the greatest restrictions on the use of 
the above values, and only under such reserve is to be understood 
what is hereafter added. As regards the analysis of the single sub- 
stances, we are inclined to believe that only in amphopeptone B, is 
there a difference in the percentage of carbon greater than the ordi- 
nary differences naturally to be expected in amorphous materials so 
difficult to prepare. 
Amphopeptone A, with the lowest percentage of carbon, has 
already been described as a mixture of fibrin-peptone and mucin- 
peptone. If we have succeeded in removing the latter, by using 
