COMPARISON OF AMERICAN WHEATS. 17 
With regard to color, the relation is not so plain. With hard red 
spring wheat the color seems to vary somewhat with the percentage 
of sound wheat, but with the other classes there is no great regularity 
so far as the averages are concerned. 
A further analysis of Table III reveals the greater value of test 
weight and percentage of sound wheat in judging quality when these 
two factors are considered together. It will be noted that the wheat 
of highest quality from the standpoint of yield and color is both high 
in test weight and in percentage of sound wheat and that the wheat 
of lowest quality is low both in test weight and in percentage of sound 
wheat. On the other hand, these figures would seem to indicate that 
a sample which is low in test weight still gives a fairly high yield of 
good-colored flour provided it is sound. They would also seem to 
indicate the converse of this, that a sample low in percentage of 
sound kernels but high in test weight may be of fairly good quality 
as far as yield of flour and color are concerned, which indicates that 
the percentage of unsound wheat is not always an absolute measure 
of the extent of damage. 
INSEPARABLE FOREIGN MATERIAL, FLOUR YIELD, AND COLOR 
OF BREAD. 
In most of the samples milled, even after cleaning and scouring, 
there remained small percentages of weed seeds, dirt, chaff, and other 
grains which were ground when the wheat was milled. With the 
wheat of all classes except the spring wheat, this was such a small 
amount in the average sample as to be almost negligible. With 
spring wheat, foreign matter consisting of a variety of weed seeds 
and other grains, particularly wild oats, was present in amounts 
sometimes ranging higher than 1J per cent. The only noticeable 
effect of this material on the milling quality as revealed by a study 
of averages is a reduction of milling yield, as is evidenced in Table 
IV. This is what would be expected, only small quantities of these 
substances getting into the flour, as they go largely into the bran 
and shorts. No effect on the color of flour or bread is apparent from 
these figures. The effects of specific impurities, such as rye, corn 
cockle, kinghead, and vetch, have been described by R. C. Miller 1 
and investigations along this line are being continued. 
1 Miller, R. C. Milling and baking tests of wheat containing admixtures of rye, corn 
cockle, kinghead, and vetch. U. S. Dept. Agr. Bui. 328, 24 p., 10 fig., 2 pi. 1915. 
