196 REPORT OF THE CHEMIST OF THE 
recently reported by Winterstein and Thény’ as being found in 
emmenthaler cheese. Excepting cadaverine and guanidine, 
thev had also been previously found, though not reported, in 
American cheddar cheese in this laboratory. It is very prob- 
able that other amido compounds will be found sooner or later, 
among the products formed by the tryptic, if not the peptic, 
digestion of milk-casein and of cheddar cheese. 
In cheese we find, earlier or later, during the ripening process 
a series of compounds and groups of compounds, which, so 
far as we know at present, appear in something like the follow- 
ing order of succession: (1) Paracasein, (2) unsaturated para- 
casein lactate, (8) paranuclein (pseudonuclein), (4) caseoses (al- 
bumoses), (5) peptones, (6) amido-acid compounds, and (7) am- 
monia. After the early stages of ripening, we have present at 
the same time all these different compounds and groups. 
We will consider methods for the separation and estimation 
of the proteolytic products found, first in cheese, and, second, 
in milk, following the general order indicated above. It may 
be well to say at the outset that, in dealing with the separation 
of nitrogenous bodies so complex in composition as those men- 
tioned above and occurring in very variable quantities, we can, 
in the study of milk and cheese problems, hope, at present, 
only to approximate accurate quantitative results. While we 
have in the Nencki method a very accurate means of estimating 
ammonia, the methods used in separating peptones from amido 
compounds can not be relied upon to give us more than ap- 
proximate results. 
I. METHODS FOR THE SEPARATION AND ESTIMATION 
OF THE NITROGEN COMPOUNDS OF CHEESE. 
We will present our description and discussion of the methods 
used for the separation and estimation of the nitrogen com- 
pounds of cheese in the following order: 
1. Obtaining sample. 
2. Determination of total nitrogen in cheese. 
5. Extraction of water-soluble products. 
Feit. f. Phys. Chem., 36: 28 (1902), 
