SEED ANALYSIS 



75 



different parts of the bag or container, usually from the top, 

 middle, and bottom. From the sample from 2 to 5 grams are 

 weighed out, and the impurities and desirable seeds are then sepa- 

 rated, usually by means of a lens like the one in Figure 72. By 



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 quarters mustard 



FIG. 73. Some weed seeds and fruits commonly found among Red Clover 

 seeds. Enlarged and about natural size. From Farmers' Bulletin 455, 

 U. S. Dept. of Agriculture. 



dividing the weight of the desirable seeds and the weight of the 

 impurities by the number of grams analyzed, the percentage of 

 each is obtained. Thus, if 5 grams are analyzed and the weight 



of the desirable seeds found is 4.8 grams, then -- = 96 per cent, 



o 



which is the percentage of purity. In determining the kinds of 



