8 BULLETIN 328, U. S. DEPARTMENT OF AGRICULTURE. 
addition to the regular grain-cleaning machinery commonly found 
in mills, is that of floating it out with wheat washers, specially 
devised machines for cleaning smutty wheat. Since installing this 
equipment is expensive, few mills have such f acuities, and they must 
depend on the ordinary grain cleaners, which remove but a small 
percentage of the kinghead seed, often present in quantities as high 
as 3 or 4 per cent. Unless wheat that contains large amounts of 
kinghead seed is mixed with a sufficient quantity of clean wheat to 
reduce the percentage of kinghead to a minimum, the flour produced 
will be of inferior quality. Such flour contains black specks, which 
injuriously affect the quality of the bread both in color and texture. 
The writer secured in a country mill samples of flour milled from 
wheat containing about 2 per cent of kinghead seed. Baking tests 
of these samples showed that both the color and the texture of the 
loaf were very seriously affected. "When milled alone, kinghead seed 
Fig. 3.— Wheat containing 28 per cent of kinghead seed and 3.5 per cent of other foreign matter, as unloaded 
from a vagon at a country elevator. (Natural size.) 
gave a very low yield (less than 16 per cent) of flour, which was dark 
gray in color. The flour was readily reduced, the bulk of it being- 
made on the break rolls and the first reduction. On account of the 
dark color of this flour, a mixture of 1 per cent of kinghead seed in 
wheat when milled is noticeable in the flour. When wheat con- 
taining 10 per cent of kinghead was milled into three grades of flour, 
the injurious effects of this so-called inseparable ingredient were in 
evidence in all grades, as shown by the results of the baking tests 
given in Table VI (p. 16). 
Figure 3 shows a sample of spring wheat as grown and delivered to 
an elevator by a farmer. This sample contained 28 per cent of 
kinghead seed by weight, in addition to 2 per cent of rye and 1.5 per 
cent of wild oats. On account of the excessive amount of this prac- 
tically inseparable weed seed in the wheat, the price and grade were 
greatly reduced, and, as with the sample which contained corn cockle, 
a heavy dockage was assessed by the grain buyer. 
