FOODS — HUMAN NUTRITION". 559 



a sufficient amount of wheat of one variety was purchased to make all the 

 milling tests for each year. From the results of these tests, which are presented 

 in detail, the author concludes that the presence of more than 2 per cent of any 

 of these impurities in wheat as milled is detrimental to its milling and baking 

 qualities. The deleterious effects of rye are, however, less pronounced than 

 those of corn cockle, kinghead, or vetch seed. The presence of 2 per cent or 

 more of rye lowered the quality of the bread. Other conclusions drawn are as 

 follows : 



" 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 characteristic of 

 vetch. 



" Corn-cockle seed is a more objectionable impurity in wheat than rj'e, king- 

 head, or wild vetch, since it contains a poisonous element known as saponin, 

 or sapatoxin, the presence of which is very undesirable in flour or bread." 



Chemical analyses of the wheat, of the impurities, and of flour containing 

 admixtures of the impurities were made and the results indicated that " the 

 flour from the different impurities was distributed to some extent in all three 

 grades of flour, a larger proportion in most instances going into the first-clear 

 and second-clear flours." 



The milling of rice and its mechanical and chemical effect upon the grain, 

 F. B. Wise and A. W. Broomell {U. S. Dept. Agr. Bvl. 330 {1916), pp. 31, figs. 

 11). — The first part of this bulletin contains a detailed description of the 

 physical and microscopic structure of the rice grains as well as a discussion 

 of the evolution of methods of rice milling. The more primitive methods and 

 the various steps of the modern process, especially the different machines em- 

 ployed, are described at length. 



In a study of the mechanical effects of milling upon the rice grains 56 series 

 of sampes of rice of the Honduras type and 25 similar series of samples of the 

 Japan type Avere secured from modern mills in various parts of the rice-growing 

 belt. These represented various grades and qualities of rough rice. For the 

 purpose of comparison, these samples were divided according to the size of 

 the particles into five divisions, as follows : Whole grain, % grain, \ grain, J 

 grain, and less than J grain ; the weight of each division and the percentage 

 it formed of the whole sample being determined. To determine the effect of 

 milling on the weight of the kernels, 9 series of samples of the Honduras type 

 and 5 series of the Japan type of rice were examined, 250 whole grains being 

 counted and weighed and from this the weight of 1,000 grains calculated. The 

 results of these tests may be summarized as follows : 



" Excessive breakage occurs when rice of the Honduras type is milled in a 

 * plantation huller,' and the finished product may have less than 10 per cent 

 of whole grains. The Honduras type of rice milled in a modern plant is broken 

 to a considerable extent during the scouring process, which reduces its whole- 

 grain content from 75 per cent as it leaves the paddy machine to 50 per cent as 

 it leaves the brush. The Japan type of rice, on account of its shape, is broken 

 to a less extent, and under similar conditions averages 92 per cent and SO per 

 cent, respectively, of whole grains. 



" Approximately 10 per cent of the weight of the rice kernels of both Hon- 

 duras and Japan types is removed by tlie scouring off of bran coat and germ. 



