186 PEARL— STAPLE COMMODITIES AND 



States compiled by the Department of Commerce. In a few cases 

 where it has been clear from information available to the Food Ad- 

 ministration that the official figures of the Department of Commerce 

 were in error we have not hesitated to use other and, we believe, 

 more correct statistics, but in each such case specific notation of the 

 fact is made in the detailed report. 



In the computation of nutrient values use has been made chiefly 

 of the factors given by Atwater and Bryant.*' It has been neces- 

 sary, in some cases, to supplement their tables from data given by 

 Leach'' and Henry and Morrison.^ 



All calculations in this work have been repeatedly checked and 

 every possible precaution taken to guard against error. It is too 

 much to hope that so extensive a piece of statistical work should be 

 without errors, but I hope that their number is small and their net 

 significance in the final results negligible. 



II. The Consumption of Human Food in the United States. 



Hitherto there have been available only the roughest guesses as 

 to the total domestic consumption of all but a few items of food, 

 such as wheat and sugar. If anyone were confronted with the 

 naive and simple question, " How much corn, or oats, or molasses, 

 or fish, or milk, or nuts," or any one of a long series of other foods, 

 " is consumed annually in the United States as human food," no 

 accurate answer could be given. Yet the question is obviously a 

 fair one, and one which somebody in the nation ought to be able to 

 answer with a considerable degree of accuracy. For some twenty- 

 odd great staple commodities or groups of like commodities we are 

 now in a position to present figures of a relatively high degree of 

 accuracy as to consumption. On the basis of these figures it is 

 possible to discuss effectively many interesting and important prob- 

 lems ; such as, for example, that of the relative importance of great 



6 Atwater, W. O., and Bryant, A. P., " The Chemical Composition of 

 American Food Materials" (Corrected April 14, 1906), U. S. Dept. Agr. 

 Office of Expt. Sta. Bulletin 28 (revised edition), 1906. 



^ Leach, A. E., " Food Inspection and Analysis." Third edition, revised 

 and enlarged by A. L. Winton, New York, 1913. 



8 Henry, W. A., and Morrison, F. B., " Feeds and Feeding." Sixteenth 

 edition. Madison, 1916. 



