PHYSIOLOGY: W. O. FENN 
537 
Decrease of Alcohol 
7 
Ma~cit 0.05M 0.02 O 
CaCk 0 0,037 006 
FIG. 2 
Antagonism between CaCh and Na-citrate in gelatine. Decrease of alcohol required 
for precipitation is plotted as ordinates (as 12 minus the number of cc. of 95% alcohol added 
to 5 cc. of the gelatine-salt mixtures in order to produce an opaque precipitate). As abscis- 
sae are plotted the concentrations of NaCl and CaCl2 simultaneously present in the gelatine 
before titrating. The dotted line represents the additive effect. A pure grade of com- 
merical gelatine was used in 3% solution. Each point represents the mean of two 
titrations. Each titration is accurate to 0.2 cc. The gelatine was always allowed to stand 
at least 15 hours in an incubator at 26*'C. in order to reach equilibrium. 
Decrease of /Alcohol 
MaCl 
CaCl 
Antagonism between NaCl and CaCl2 in gelatine (for explanation see figure 2). 
maximum the molecular proportion of NaCl to CaClz is 100 to 17. 
At the 
