The Colloidal Swelling of Wheat Gluten, 
9 
In Table 5 are given the figures showing the effect of varying 
concentrations of four salts and also of glycocoll on the absorp- 
tion of water by gluten in the presence of 0.01 N lactic acid. 
The results are shown graphically in Figure 3. 
In all cases there is a rapid decrease in water absorption with 
an increase in the concentration of the salt. In the higher con- 
centrations of phosphate and tartrate, the gluten disk drops to 
a weight below that of the original moist disk. 
Table 5. — 0.01 N lactic acid and varying concentrations of salts 
and of glycocoll. 
Wt. of water absorbed in g. per g. of moist gluten 
Cone, of salt 
0.01 N lactic acid and 
solution 
KCl 
K2HPO4 
K2C4H4O6 
CaCl2 
Glycocoll 
No salt 
1.70 
2.12 
1.87 
2.02 
1.70 
0.001 M 
1.23 
1.17 
1.18 
1.50 
0.002 M 
1.09 
0.85 
0.85 
1.21 
1.57 
0.005 M 
0.74 
0.49 
0.26 
0.85 
1.65 
0.01 M 
0.46 
0.06 
—0.02 
0.43 
1.29 
0.02 M 
0.21 
—0.18 
—0.11 
0.11 
1.21 
0.04 M 
—0.03 
—0.21 
—0.14 
0.00 
1.14 
0.1 M 
0.71 
0.2 M 
0.53 
0.4 M 
0.50 
At the concentration of 0.02 M the order of salts as regards 
their effect in diminishing absorption is the same as found by 
Fischer for gelatin and fibrin, namely: Chloride, tartrate, and 
phosphate. That the relative position of the curves for the four 
salts is not the same for all concentrations may or may not be 
significant. We do not think the matter due to experimental 
error. There is undoubtedly a very important relation between 
the exact concentration of the acid and the inhibiting effect at 
different concentrations of the salts. Of special interest is the 
fact that glycocoll behaves like a salt in reducing the swelling of 
gluten in acid solution. The effect, however, is less marked than 
with the different salts studied. 
A series of photographs will help to make evident the signifi- 
^iant differences iij the swelling of gluten under different conditions. 
