620 METABOLISM, NUTRITION AND DIETETICS 



by deficiency in the food of certain substances minute in amount 

 but essential to proper nutrition. These substances are some- 

 times termed ' vitamines.' But their chemical nature is imper- 

 fectly known, and there is no certainty that the bodies which exert 

 the beneficial influence belong to the same chemical group.* The 

 best investigated representative of the important food constituents 

 in question is a basic substance separated by Funk from the polish- 

 ings of rice, and named by him ' vitamine.' Polished rice is rice 

 deprived of the outer coats by modern milling processes, and the 

 polishings are the coats which have been removed. It is a general 

 rule that the vitamines in the cereals, including wheat, maize, oats, 

 and barley, are contained exclusively in the outer coats. Since the 

 introduction of steel rollers instead of the primitive millstones 

 which used to crush the whole grain, beri-beri, a disease characterized 

 by inflammatory and degenerative changes in the peripheral nerves 

 (peripheral neuritis) and consequent paralysis, has greatly increased 

 among the rice-eating Japanese. In Bengal, although much rice 

 is eaten, there is practically no beri-beri, as country rice and not 

 the highly polished variety is consumed. When birds e.g., pigeons, 

 are fed on polished rice, polyneuritis similar to that seen in human 

 beri-beri is produced, and both in man and in birds the condition 

 is quickly cured by reverting to rice prepared according to the old- 

 fashioned methods, or by adding the polishings or an alcoholic extract 

 of them containing the essential substance, or the isolated base itself. 



The addition of various legumes to the diet, or alcoholic extracts 

 of these, will produce the same beneficial effect (McCay). Potatoes, 

 carrots, fresh vegetables, lime and other fruit juices, also certain 

 animal foods, such as fresh milk, fresh meat, and yolk of egg, are 

 all valuable, in addition to their ordinary nutritive constituents, for 

 their content of vitamines. Yeast contains them in exceptionally 

 large amount, and it is possible, though not proved, that such 

 fermented liquors as beer, or some varieties of it, mav derive some 

 part of their value from these substances liberated both from the 

 yeast and the barley and not destroyed in the process of brewing. 



Since vitamines exert so great an effect on nutrition and growth, 

 it might be expected that their absence would tell on those glands 

 of internal secretion which appear to be concerned in the metabolism 

 of growth. As a matter of fact, it has been found that in pigeons 

 suffering from the typical deficiency disease beri-beri, certain of these 

 glands show marked changes. The thymus gland, normally very 

 large and persistent in these birds, can be caused to atrophy com- 

 pletely by a diet of polished rice. Changes also occur in the pituitary, 

 and decided atrophy in the testes and ovaries (Funk and Douglas). 



* It might be better in the present state of our knowledge to avoid giving 

 thcs3 bodies a name which may easily mislead. They might possibly be pro- 

 visionally spoken of as " vitines," a term involving no assumption as to their 

 chemical nature, and implying only their importance in the nutritional pro 

 cesses associated with the life (and growth) of the tissues. 



