298 DIETETIC OKFJCIENCV. 



remained a mystery, in spite of strenuous research carried out 

 from the bacteriological and pliarmacological ])oints of view. 

 The apparently epidemic character of the disease naturally sug- 

 gested a causal organism, although equally naturally any disease 

 becomes epidemic whenever large num1>er of sensitive recipients 

 are exposed to a common causal environment, irrespective of the 

 nature of the cause. Toxic agency was also conjectured, and 

 nuich fruitless labour was expended in seeking for the toxin. 

 Even to-day eminent adherents both to the infection and to the 

 intoxication theories are to be found, and even so recently as 

 last year Abderhalden. of Halle, and Caspari, of Berlin, ex- 

 pressed the opinion that the case for the '' deficiency theory " as 

 against the " intoxication theory " was by no means proven. At 

 the same time the evidence in favour of the vitamrne-hunger 

 theory is strong enough to have convinced the majority of inves- 

 tigators that inn' beriberi is to be regarded as the clearest exist- 

 ing case of a deficiency disease. 



o - 



A brief historical resume of the main lines of investigation 

 as reviewed bv Funk, and others, mav be given. 



Wernich, ( 1878) and \'an Leent ( 1880) are stated to be the 

 first investigators who connected beriberi (kak-ke) with the 

 consumption of rice, and in 1882 Takaki (working on the idea of 

 protein deficiency ) effected an enormous reduction in the beri- 

 beri mortality in the Japanese navy by the empirical introduction 

 of a mixed diet in place of the earlier rice ration. 



Vordermann, on the basis of statistical evidence collected 

 from Japanese prisons in 18(15-96, at the suggestion of Eykman, 

 clearly demonstrated a close connection between the occurrence 

 of the disease and the prolonged consumption of polished rice. 

 Braddon confirmed this work in the Malav Peninsula, and ob- 

 served that the Tamils, a class of natives who generally use un- 

 polished rice, remain free from the disease. 



The clue to the connection between the ])olishing of rice and 

 the occurrence of beriberi was in part suggested by the extraor- 

 dinary increase of the disease which followed upon the spread 

 of European culture in the East, towards the end of the nine- 

 teenth century. The extensive importation of high-grade Euro- 

 pean machinery during this ])eriod led to a higher degree of 

 refinery of general milling ]>r()ducts. More ])articularly the clean- 

 ing and de-branning of rice which had previously been imper- 

 fectly carried out, chiefly by crude hand-mills, was now per- 

 formed by subjecting to an extremely thorough mechanical 

 polishing by leather straps. This effected a practically com])lete 

 removal of the outer layers of the grain, and with them, as subse- 

 quent research showed, certain physiologically essential com- 

 pounds located on the exterior of the kernel — the " vitamines." 



Before passing on to a sketch of the work carried out in con- 

 nection with the chemical nature of the yitamines, it may be of 

 interest to indicate the clinical and i)athological findings of beri- 



