The Colloidal Swelling of Wheat Gluten. 
21 
washing agents give higher figures for the three factors on the 
low-grade flour than for the corresponding factors on the other 
two flours. 
When the washing agent is sodium chloride solution of higher 
concentration than 0.5 per cent, the wet gluten decreases slightly, 
whereas the dry gluten and protein remain practically the same. 
With all three concentrations of salt the two latter figures are 
practically the same as with distilled water, whereas in all cases 
the salt solution gives higher figures for wet gluten than does 
water. Dipotassium phosphate solution of concentration M/10 
gives much lower figures for all three factors than does sodium 
chloride solution, tap water, or distilled water. As the concentra- 
tion of the phosphate solution becomes less the figures for all 
three factors become larger but even with M 40 phosphate are 
not as great as the corresponding figures with any of the sodium 
chloride solutions. 
In Table 11 are given the percentages of wet gluten, dry 
gluten, and protein for a patent flour and a low-grade flour when 
seven different concentrations of salt solution as well as distilled 
water were the washing agents. The percentages given are in 
all cases averages of three sets of figures. The flours were ob- 
tained from 1915 wheats, while those used in obtaining the 
results of Table 10 came from 1914 wheats. 
From the unbleached flour a smaller per cent of wet gluten 
is obtained when water is the washing agent than when any of 
the salt solutions are the washing agents. With increasing con- 
centrations of sodium chloride solution the percentage of wet 
gluten rises, reaching a maximum when 1.00 per cent salt solution 
is the washing agent. Very striking is the fact that the per- 
centages of dry gluten and of protein are the same whether 
distilled water or one of the salt solutions is the washing agent. 
In other words, washing with any of the salt solutions brings 
about swelling of the gluten due to water absorption. A 0.5 per cent 
magnesium chloride solution gives similar results. 
