6 BULLETIN 215, U. S. DEPAETMENT OF AGRICULTURE. 



usually of a mixture of bran and the finely divided offal analogous to 

 red dog flour of the wheat mill. The ground corn cake is often an 

 ingredient of corn feed. 



COMPOSITION OF THE PRODUCTS OF CORN MILLING. 



The analyses reported under this head are of samples obtained from 

 corn mills in different sections of the country. With few exceptions 

 the samples of meal were taken at the mills by the authors, so far as 

 possible from the streams of corn going to the mining apparatus and 

 of finished products going to the packers. They represent the prod- 

 ucts of forty-one mills located in thirty-two towns and seventeen 

 States. The samples were shipped without delay to the Chicago 

 Food and Drug Inspection Laboratory for analysis, the determina- 

 tions being made as soon as the samples were received. 



METHODS OF ANALYSIS. 



The analyses were made by the methods of the Association of 

 Official Agricultural Chemists, with the exception of the acidity, 

 which was determined by the method employed by Schindler 1 and 

 described in detail by Black and Alsberg. 2 



The determination of moisture by drying for five hours at the 

 temperature of boiling water in a current of dry hydrogen was carried 

 out in the apparatus devised by Winton. 3 The results obtained by 

 means of this apparatus were about 1 per cent higher than those 

 obtained by drying for the same length of time and at the same 

 temperature in an open dish. The reason for this difference is not 

 clear, but is probably, in part at least, physical. The fact that the 

 difference was well marked in the case of degerminated meal contain- 

 ing less than 1 per cent of fat precludes the assumption that the cause 

 lies in the prevention of oxidation by the hydrogen method. 



Great annoyance and sometimes heated disputes have resulted from 

 discrepancies in the results of a moisture determination by different 

 methods and in different laboratories, particularly those of the buyer 

 and seller. As the process used in these experiments has given con- 

 cordant results in mill laboratories as well as in those of the depart- 

 ment, it is believed that the extra labor and expense involved as 

 compared with drying in an open dish will recommend it, at least for 

 use in standardizing such shorter processes as the official or trade 

 chemist may find convenient. In this connection attention is directed 

 to the modification of the Brown and Duvel apparatus adapted for 

 the determination of moisture in meal which has recently been 

 devised by Cox. 4 It is hoped that this method will be of great value 



i Loc. cit. p. 37. 



2 Loc. cit. p. 10. 



3 Winton, A. L. Conn. Agr. Expt. Sta. Rept., 1889, p. 187; Leach, Albert E. Food Inspection and 

 Analysis, p. 62. 



4 Cox, John H. A Special Flask for the Rapid Determination of Water in Flour and Meal. U. S. Dept. 

 Agr. Bui. 56. 



