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different from the common proteins, carbohydrates, and fats. 

 If these essential materials are persistently absent from the 

 diet, the normal metabolic processes are likely to become 

 disturbed andMeranged, culminating in pathological changes of 

 a more or less pernicious character. 



The justification of this hypothesis is to be found in the 

 remarkable light which it throws upon our knowledge of a 

 number of diseases which appear to be caused by a too rigid 

 restriction of diet. Such diseases have been grouped together 

 under the term " Deficiency Diseases," and include beri-beri, 

 pellagra, scurvy, rickets, and other less well-defined conditions. 

 We shall see that a certain amount of evidence has been 

 accumulated to show that, in each case, the condition is 

 attributable to the absence from the diet of an essential material, 

 termed by Casimir Funk a vitamine, which is more or less 

 specific in its action in preventing the onset of the disease. 



Beri-Beri 



Beri-beri is a disease which used to be common in Japan, 

 the Malay Peninsula, and the Philippines — countries where rice 

 is the staple article of diet. That rice consumption was really 

 the cause of beri-beri was suggested as early as 1878, but 

 Eykman was the first to bring forward, in 1897, evidence which 

 seemed to establish a close connection between the use of 

 " polished " rice and the appearance of the disease. 



The rice grain, as will be seen from the accompanying 

 figs. 1 and 2 (from Dr. Casimir Funk's article in the 

 Ergebnisse der Physiologie, vol. xiii. 191 3), consists of an inner 

 part and an outer husk. The inhabitants of the regions just 

 referred to live almost entirely on rice which has had its husk 

 removed— polished rice — and Eykman showed that the addition 

 of the missing husk, rice bran, or the substitution of unpolished 

 for polished rice, was sufficient to effect the cure of the disease 

 and prevent its subsequent recurrence. 



The nature of the evidence is interesting. Eykman found 

 that if birds are fed on polished rice, a condition is produced 

 which is analogous to the disease of beri-beri in man. The 

 characteristic symptoms in man are such as arise from degene- 

 ration of peripheral nerves, viz. paralysis, muscle atrophy, 

 contraction of the extremities. Death ensues from heart 



