24 BULLETIN" 328, U. S. DEPARTMENT OF AGRICULTURE. 
Special experiments were made to ascertain what effects the 
presence of rye, kinghead, corn cockle, or wild-vetch seed in wheat 
has on milling and baking qualities. 
A sufficient amount of wheat of one variety was purchased to make 
all the milling tests for each year, in order to have a basis for com- 
parison of all tests with the impurities. Different percentages of each 
impurity were mixed with wheat samples, which were then milled 
and baking tests made with the flour. 
The results of these tests show that the presence of more than 2 
per cent of any of these impurities in wheat as milled has detrimental 
effects on the milling and baking qualities. 
The deleterious effects of rye in wheat are less pronounced than 
those of corn cockle, kinghead, or vetch seed. If present in wheat 
in amounts as high as 2 per cent or more, rye lowers the quality of the 
bread. 
Corn cockle seems to have exceedingly injurious effects on the 
volume, color, and texture of the loaf, and when present in amounts 
of 3 per cent or more reduces the percentage of water absorption of 
the flour. 
Kinghead in wheat in appreciable amounts materially lowers the 
flour yield, and the detrimental effects of this impurity in the flour 
are especially noticeable in the dirty color of the crumb and the 
coarse, uneven texture of the bread baked from such flour. 
Vetch seed in wheat will reduce the size of the loaf and give to the 
bread a yellowish tinge and a disagreeable odor and flavor charac- 
teristic of vetch. 
Corn-cockle seed is a more objectionable impurity in wheat than 
rye, kinghead, or wild vetch, since it contains a poisonous element 
known as saponin, or sapotoxin, the presence of which is very unde- 
sirable in flour or bread. 
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