
New York AGRICULTURAL EXPERIMENT STATION. 177 
TABLE III1.—CoMPARATIVE COMPOSITION OF NATURAL AND 
ARTIFICIAL PrRopUCTS. 


! 
NirROGEN EXPRESSED AS PERCENTAGE | 
or Torat NirroGEN IN Form oF | 
é | Phos- | 
Nitrogen. phorus: Ash, 


Ammonia.) Histidin.| Arginin. | Lysin. 


Per ct. | Per ct. | Per ct. 






Deity} sy Bilt 2. Guba DiSbd ole ts 

Natural product..| 7.65 | 2.36 |, 7.77.) 2.21.) 15.12 | 0.70 || 1.51 
Artificial product. 7.66 |) 2.21 7 "8.08" |}! 2.02 15.30 | 0.91 | 1.12 
Case@inuiss. srizo.. 7.34 | 3.66 


The results embodied in Table III indicate a striking sim1- 
larity in structure between the salt formed by paracasein with 
lactic acid found naturally occurring in cheese and that artifi- 
cially prepared, so far as the products of hydrolysis enable us 
to draw conclusions. This has reference simply to the linking 
of the nitrogen in the proteid as a whole. 
Later, it will be seen that what we had really prepared in 
both cases was the saturated salt formed by paracasein with 
lactic acid and not the unsaturated salt; and, as we shall show, 
the unsaturated salt is the one soluble in dilute solution of 
sodium chloride. The formation of these combinations with 
acids probably does not involve any deep-seated rupture of the 
proteid molecule, as can readily be inferred from the results 
given in Table III with casein, which furnishes both saturated 
and unsaturated salts with acids. It is evident that, in the 
preparation of the artificial salt identical with the proteid ex- 
tracted by common-salt solution from cheese, the chief, if not 
the only, active factor is an acid. 
SALTS FORMED BY COMBINATION OF PARACASEIN WITH ACID. 
Action of lactic acid used in different amounts wpon paracasem. 
—in the manufacture of cheese, the lactic acid that combines 
with paracasein is formed by fermentation of milk-sugar, the 
lactic acid combining with the paracasein as rapidly as the acid 
is formed. It appeared desirable to study the action of lactic 
acid, used in different amounts, as it is formed in the fermenta- 
12 
