METHODS OF SAMPLING. 9 



sugar by digestion in the cold. The sampling and subsampling of 

 the beets are important details, for unless the sample is representative 

 the results obtained are of little value. 



SAMPLING FROM THE FIELD. 



The beet chemist is often called upon to take a sample from the 

 field. This sample should accurately represent the whole crop to be 

 of any value as an index of the condition of the field. There are 

 many methods of accomplishing this, some of a mathematical nature. 

 The method to be employed depends somewhat upon the size of the 

 field and the purpose for w r hich the results are to be used. If the plat 

 is small and it is the purpose to sample often, then a smaller sample 

 may be used, but when the fields are extensive a larger sample should 

 be drawn. 



As an example of a mathematical method of sampling, the following 

 is given : Look over the plat, noting the stand, and remove all beets 

 that are not up to the average condition of the field. Go through 

 again and dig every fourth to tenth beet (according to size of plat) 

 for the analytical sample; every twentieth beet should be taken if 

 the plat is very large. From 20 to 100 beets should constitute a 

 sample. Another method is to remove all the beets in one row or a 

 measured portion of a row and use these as the analytical sample. 

 Care must be exercised that the row selected is representative. 



To ascertain for factory purposes whether or not the crop is ripe 

 and ready for harvest, the general practice is to walk across the field 

 from one corner to the opposite one, noting the stand and the general 

 condition of the beets as indicated by their leaves, general appearance, 

 etc.; then on returning to dig from 5 to 20 beets at random, selecting 

 those in average condition. Here the judgment of the sampler is 

 wholly relied upon, but with experience and a knowledge of the variety 

 under cultivation, a representative sample should be obtained. 



Whatever method is used, it is essential in digging and cleaning 

 the beets not to injure the skin and not to break the roots too short. 

 The topping should consist only in removing the leaves, the crown 

 being left in place for the chemist to remove; this prevents drying 

 of the sample, etc. 



SAMPLING FROM PILE, WAGON, OR CAR. 



In sampling from a pile instead of from a field the judgment of the 

 sampler again must be relied upon. A good procedure is to examine 

 the pile of beets, noting the general shape and average size, and then 

 to select from 10 to 50 beets for analysis, depending on the size of the 

 pile. A proportionate number of large, small, and irregular-shaped 

 beets should be used as they occur in the pile. 



ID drawing samples from a wagonload or carload of beets, it is cus- 

 tomary to adopt one of the following procedures: When a dumping 



4426 Bull. 14611 2 



