■368 Missouri Agricultural Report. 



liable to be present. All the foreign seeds (except certain adulterants), 

 including other crop seeds and weed seeds, also inert matter, as pieces of 

 stems, chaff, sand and badly broken seeds, are to be separated from the 

 kind under test. Both plump and shriveled crop seed should be classed as 

 ' ' pure seed. ' ' While the shriveled seed very evidently may be worthless, 

 it nevertheless is a part of the crop seed, and its worthlessness will appear 

 in the subsequent germination test. 



If certain specific adulterants, as trefoil, sweet clover, bur clover, 

 •Canada bluegrass and rye-grass, are found, the adulterant seeds are left 

 mixed with the crop seed when the other foreign seeds are separated. The 

 proportion of the adulterant is then determined by count from a part of 

 the mixture. 



If certain kinds of foreign crop seeds or of weed seeds are especially 

 abundant it may be desirable to keep them separate from the rest in 

 order to determine their quantity, but if not, the foreign matter for con- 

 venience may be mixed together irrespective of its character. In official 

 tests the foreign seed and the inert matter are separated, their quantities 

 Ijeing determined individually. After the pure seed and the foreign ma- 

 terials of the sample have been separated the proportion of pure seed is 

 <ietermined by comparing its weight with that of the entire sample, ex- 

 pressing the result in per cent. If quantities of seed weighing 614 shots 

 or 121/2 shots have been taken for the original test sample, each ^/^g-shot 

 weight of pure seed represents 1 per cent or one-half of 1 per cent, re- 

 spectively. 



Determination of Adulterants.'^ — When an adulterant is found and 

 its kind ascertained by examination, its quantity must be determined. 

 When such seed as that of trefoil, sweet clover, Canada bluegrass, and 

 other kinds have been used, their separation from all the pure seed of a 

 test sample is laborious and not justified by the information gained. 

 "Since the weight of these seeds is approximately the same as that of the 

 ■seieds with which they are mixed, their relative proportion to pure seed is 

 determined by count. After all other foreign seeds and other ma- 

 terials have been separated from the pure seed and adulterant together 

 1,000 seeds of the mixed crop seed and adulterant are counted out indis- 

 criminately. This number of seeds is then carefully separated into pure- 

 crop seed and adulterant and the number of each ascertained by actual 

 count. If a sample of red clover seed is found to be adulterated with trefoil 

 to the extent of 400 seeds in 1,000 seeds of the mixture, the trefoil is de- 

 termined to be 400 -^ 1,000=40 per cent of the mixture. If other foreign 

 matter in the sample amounts to 15 per cent, the clover and trefoil mix- 



a See Farmers' Bulletin 382, entitled "The Adalteration of Forage-Plant Seeds.' 



