The Colloidal Swelling of Wheat Gluten. 
19 
for salt mixtures for use in bread making. These mixtures con- 
tain ammonium chloride and calcium sulphate. It is stated that 
these substances are of value in that they effect a saving in yeast, 
promote its growth, etc. While these substances may promote 
the growth of the yeast plant, they also certainly change the 
physical character of the gluten. Their effect in modifying the 
character of the gluten must be taken into account in explaining 
their action. 
It seems probable also that the beneficial results obtained 
from the use of mineral ''flour improvers" depend in part at 
least on the effect produced by these substances in modifying 
the physical properties of the gluten. These improvers usually 
contain phosphates, which are among the most effective sub- 
stances in inhibiting water absorption by gluten. Most pro- 
nounced results are obtained with the use of these improvers on 
weak flours such as are grown in the British Isles. These flours 
have been shown to be exceptionally low in content of soluble 
salts and especially in phosphates. 
EXPERIMENTS ON THE WASHING OF GLUTEN. 
METHODS FOR THE DETERMINATION OF WET GLUTEN. 
Experiments were carried out on the washing of gluten from 
flour using various solutions as well as distilled water and tap 
water. The solutions used were sodium chloride of several 
different concentrations, potassium phosphate, dilute hydro- 
chloric acid, magnesium chloride, and hydrochloric acid in com- 
bination with sodium chloride. 
The method employed for washing the starch from the gluten 
was in all cases the same. Ten grams of the flour were weighed 
out and made into a stiff dough in a round-bottomed porcelain 
cup. The cup was then filled with water or solution and allowed 
to stand for exactly one hour. In the case of all of the flours 
except the low grade, 6 cc. of liquid were used in making the 
dough; in the case of the latter, 6.5 cc. were used. After being 
allowed to stand under the liquid for one hour the ball of dough 
was carefully worked under a stream of the solution or water for 
exactly 14 minutes. It was then removed from under the stream 
and worked in the fingers for 1 minute, placed on a tared dish, 
and weighed. This weight was recorded as the weight of wet 
gluten. The mass was then dried to constant weight at 110° 
C. and again weighed; this was recorded as the weight of dry 
gluten. In all cases, unless otherwise stated, the solution in 
which the gluten was to be washed was used in making up the 
dough and was placed over it while standing. Care was taken 
