32 PHYSIOLOGY AND NATIONAL NEEDS 



local customs, were supplied with different kinds of 

 rice, so tlie conditions for controlled observations 

 were ready to hand. 



In 37 prisons unpolished rice was employed : only 

 one of these prisons developed cases of beri-beri. 

 In 13 prisons the rice used was polished rice mixed 

 with unpolished : in six of them beri-beri developed. 

 Out of 51 prisons where the rice eaten was entirely 

 of the polished variety so many as 36, or over 70 

 per cent, developed cases of the disease ! If instead 

 of considering the prisons we count individuals, we 

 find from Eijkman's data that for each 10,000 of 

 the prison population there was only one case among 

 those eating unpolished rice, 416 on the mixed rice 

 dietary, and no less than 3900 on polished rice. 

 Confirmatory observations have in later years been 

 made elsewhere, but Eijkman's figures are so con- 

 clusive that I need bring forward no others. What, 

 then, is removed by the steam mill of which the 

 importance becomes so evident in its absence ? 

 Not the main husk of the grain, for that had nearly 

 always been removed in oriental practice, but just 

 a very thin layer — the '* silver skin " — which lies 

 on the outer part of the husk-free seed, together 

 with what we now know to be also important, the 

 germ or embryo. But these structures represent 

 but a very small proportion indeed of the total 

 weight of the grain, and we know, as a matter of fact, 

 that the essential thing or things contained in them 



