8 QUICK METHOD FOR DETERMINING MOISTURE IN GRAIN. 



With the i^resent system of grain inspection, when hundreds of cars 

 must be inspected dail}'-, and the water content of the corn is deter- 

 mined only by feeling the corn with the hand or by biting the kernels, 

 any degree of accuracy is next to imj^ossible. Most of this work is 

 done in the cars on the track and sometimes when the mercury has 

 gone below the zero mark. 



THE PERCENTAGE BASIS FOR MOISTURE DETERMINATIONS. 



There seems to be a growing demand among grain men and inspec- 

 tion departments for a more definite and uniform system of grading, 

 Avhich is taking the form of an agitation for uniform rules for grades. 

 Any system of uniform grading to be effective must be based on a 

 percentage statement of the various factors which go to make up the 

 quality and condition of any particular lot of grain in order to 

 insure uniformity of application. With this in view, a considerable 

 amount of preliminary work has been done for several years in the 

 Bureau of Plant Industry, which will later aid in formulating rules 

 to place the grading of grain on a basis which will permit stating 

 the elements of condition and quality in definite terms. 



Members of boards of trade and chambers of commerce, as well as 

 most grain inspectors, have been much in doubt as to the practica- 

 bility of incorporating in their rules a percentage statement of 

 moisture in grain, and with the methods commonly employed for 

 making moisture determinations the percentage system is not suitable 

 to the present condition of the grain trade, save, perhaps, in a few 

 special cases. Heretofore the minimum time required to make a 

 moisture determination of a sample of grain was from six to eight 

 hours, and this was accomplished by drying a carefully weighed 

 ground sample in a glycerin oven or in a vacuum at a temperature 

 of 105° or 108° C. If the drying be done in an ordinary water oven, 

 such as is commonly used, the time must be extended to from sixteen 

 to twenty hours. To each of these periods must be added the time 

 occupied in grinding and weighing the sample preparatory to drying, 

 and likewise the time required for the samples to cool in the desicca- 

 tor before the final- weighing. If whole kernels are used instead of 

 a ground sample, the time required by the process at present in use 

 must be extended to from sixty to ninety-six hours. 



But, disregarding the time factor, the method outlined is not appli- 

 cable to commercial corn containing a relatively large percentage of 

 water. Practically all of the machines available for grinding sam- 

 ples of grain for analysis are of the " burr '" type, and during the 

 grinding the temperature of the grain is increased to such an extent 

 that from 0.5 per cent to 1.5 per cent of moisture is lost in the pro- 

 cess of grinding, unless the corn has been well cured and dried, in 

 which case a moisture determination is not needed. 



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