228 REPORT OF THE CHEMIST OF THE 
In neither case were we able to separate arginine, but in the 
older cheese we found putrescine, one of the reduction" produsts 
of arginine. We did not look for guanidine, but this compound 
might be expected to be present as the other cleavage product of 
arginine, and Winterstein and Thony have reported its probable 
presence in emmenthaler cheese. While there is some reason to 
believe that lysatine is composed of arginine and lysine, the point 
is not clearly settled and in our discussion we have not assumed 
this to be the case. 
It is known that lysine" yields also pentamethylenediamine 
(cadaverine) on reduction, and Winterstein and Thoény have re- 
ported the presence of the latter compound in an emmenthaler 
cheese. They do not give any facts in relation to the history of 
the cheese used in their work and we are unable, therefore, to 
make any comparison with our cheese 15 months old, in which 
we found one of the reduction products of arginine, viz.: putres- 
eine. Whether cadaverine might have been formed ultimately, 
we cannot say. 
There appears to be good evidence that there is regularly in the 
cheese-ripening process, in the case of hard cheeses like emmen- 
thaler and American cheddar, a conversion of primary into sec- 
ondary amido compounds; and these chemical changes may 
explain, perhaps, the gradual development of flavor in normal 
cheese; in other words, we may find that the changing flavor of 
cheese, aS it ages, is due, to some extent, to increasing quantities 
of secondary amido coinpounds. - 
In fiavor, the older cheese used by us was rather pungent but 
not unpleasantly so. It had a high ammonia content, which is 
a marked characteristic of cheese ripened at temperatures above 
16° to 18° C. and which also is a usual accompaniment of a pun- 
gent ilavor. In cheese ripened in cold storage, where the tem- 
perature is usually below 5° C., small amounts of ammonia are 
found and the flavor is very mild. We must bear in mind, how- 
ever, that the presence of mere traces of such compounds as 
putrescine, cadaverine and ammonia will not suffice to account 
for marked abnormal sharpness or other unpleasant quality of 
flavor in cheese, but that they gradually accumulate and finally 

11 Allinger. Zeit. f. Physiol. Chem., 293 334 (1900). 
