Kiihne and Chittenden—Peptones. 247 
purified pepsin, then the figures obtained from B and } may be con- 
sidered as representing the first gastric peptone prepared free from 
albumose. The correspondence between the two, in spite of the fact 
that by continued purification of b we succeeded in reducing the ash 
by more than 1 per cent., we think may be considered as grounds for 
this assumption. In opposition therefore to the majority of pre- 
vious statements, including our own, which as now easily understood 
referred to mixtures of albumose and peptones, there is to be noticed 
in pure amphopeptone about 1 per cent. lower content of carbon, 
about as much higher a percentage of nitrogen and 0-3-0-4 per cent. 
lower content of sulphur. 
With antipeptone, the variation from the previous results was 
less expected, for we are not inclined to believe that in our former 
long and thorough typsin digestions, any appreciable quantity of 
albumose remained and in the more recent ones, the precipitate pro- 
duced by ammonium sulphate was never abundant if the matter 
‘separated by boiling in a slightly acid solution was previously 
rémoved. The differences found, however, might be readily explained 
by the fact that the purification of the peptone had this time been 
more complete, owing partly doubtless to the formation of the 
barium compound, and partly also to the precipitation with phospho- 
tungstic acid. The content of carbon is seen to be about | per cent. 
lower, the content of sulphur likewise lower and the percentage of 
nitrogen decidedly higher, in one case as much as 4 per cent. more 
than before. The real reason for this difference in composition 
appears to us to lie in the use of much larger quantities of trypsin, 
which formerly was only possible by using large quantities of the 
gland substance, so that the fibrin-antipeptone would naturally be 
obtained mixed with the gland peptone. It is well for the future 
that we know the composition of these gland peptones, for they 
differ essentially, in the lower content of carbon (in one case 42:96 
per cent.), from all other peptones hitherto investigated. These 
bodies might be pronounced troublesome intruders with the same 
right as the mucin-peptone arising from gastric digestion, although 
we found in it, aside from the percentage composition, no reaction 
and no property which would serve to distinguish it from the other 
peptones. 
After these considerations, little stress can be laid on the differences 
between the composition of pepsin and trypsin peptones. We have 
found, however, another difference which we will examine more 
closely. 
