6 
BULLETIN 168^ U. S. DEPAETMEXT OF AGEICULTUEE. 
Bureau of Plant Industry, United States Department of Agriculture, 
have been designated as the standard on which the grades have been 
based. Copies of this circular can be secured upon application to 
the United States Department of Agriculture. This in no way>pre-' 
eludes the use of other methods of making moisture determinations, 
so long as the results are corrected to conform to those secured by 
the standard method specified. Figure 4 represents a sectional view 
of the standard tester that is recommended. The United States 
patent covering this tester has been donated to the people of the 
United States, so that the tester can be used, manufactured, or sold 
by any citizen ^\^thin the United States without the pa^anent of 
royalty. 
DAMAGED CORN. 
As sho^vn in the grade classification (Table I), the grades 1, 2, and 
3 may contain not to exceed 2, 4, and 6 per cent, respectively, of 
damaged corn, such as '^cob-rot- 
ten" corn, '^blue eyes," etc., but 
these fu*st three grades shall not 
include heat-damaged or mahog- 
any kernels. Grades 4, 5, and 6 
may contain not to exceed 8, 10, 
and 15 per cent, respectively, of 
damaged corn, a portion of which 
may consist of heat-damaged or 
mahogany kernels. The heat- 
damaged or mahogany kernels 
permissible as a part of the dam- 
aged corn shall not exceed one- 
half of 1 per cent in No. 4 grade, 1 per cent in Ko. 5 grade, and 3 per 
cent in Xo. 6 grade; but the total damaged in these three grades shall 
not exceed 8, 10, and 15 per cent, respectively. 
Types of damaged Icernels. — An attempt has been made to show in 
natural colors by means of kernels numbered 1 to 26 in Plate I types 
of kernels which should be classed as damaged. These types of 
damage range from the badly '^ silk-cut" kernels, shown in No. 1 
(front and back of same kernel), to the very badly '^cob-rotten" 
kernels shown in Xo. 26. These t}'pes also include badly shriveled 
kernels which have failed to ripen (shown by kernels numbered 14 
and 15). However, skeleton kernels similar to this type, when con- 
sisting of nothhig but the skin of the kernel or of such a character 
that they would be removed by light blowing or fanning, should be 
classed as foreign material and not as damaged corn, T}^es of such 
skeleton kernels are shown in figure 5. 
Fig. 3.— Nest ol two sieves and bottom pan used in 
grading corn. 
