342 HUMAN BIOLOGY 



nutritive requirements of the body had progressed to a 

 suitable stage. For example, although refined bolted flour 

 has been manufactured to some extent from time immemorial 

 its use never became general until after 1879, ^^ which year 

 the roller mill process for making white flour was invented. 

 Considerations of commerce, the great distance to the 

 centers of population in the eastern United States from the 

 great grain growing regions in the west, and the inevitable 

 transport of flour for long distances by ship or rail, necessitate 

 keeping qualities in flour which were entirely unnecessary 

 two generations ago when the milling industry was a neigh- 

 borhood one and the stock of flour relatively unrefined was 

 replenished at intervals of two to three weeks. We are 

 now, therefore, eating highly refined white flour, deger- 

 minated corn meal, and polished rice, in diff'erent parts 

 of the country in amounts never before approached. 



At present the annual consumption of sugar per person 

 per year in the United States is 115 lbs. The consumption 

 has increased about ten times in a century and now con- 

 stitutes as much as 8 or 10 per cent of the total energy 

 supply of many people, who are likewise consuming a high 

 intake of refined cereal products. For some years I have 

 described the typical American diet as a white bread, 

 muscle meat, sugar and potato combination. Such a mixture 

 is a failure in animal experiments and would be a failure 

 in human experience if it were not for the regular addition 

 of small amounts of certain foods which have the property 

 of enhancing the quantity of the principal articles of the 

 diet. These are especially of two classes, namely, the leafy 

 type of vegetable, and milk and other dairy products. 



From what has already been said it will be appreciated 

 that on certain kinds of diets the so-called deficiency diseases 

 due to lack of one or another vitamin will develop. Beri-beri 

 is the most widespread of these but at times in the past 

 scurvy was also of common occurrence. Epidemics of vitamin 

 A deficiency have in general affected smaller groups of 

 people. Pellagra has in certain regions reached the pro- 

 portions of a scourge. As many as 200,000 people were 

 reported sufl"ering from this disease in the United States 

 alone in 191 7. From then until the flood of 1927 in the 



