66 HAAN. 



it was closely associated with the food of the fowls. It always appeared 

 after an incubation period of varying duration (ranging from twenty to 

 thirty days, sometimes more) when the birds were fed on boiled rice, 

 the same as was given to the hospital patients. The polyneuritis could 

 not be caused by a poison present in the rice, for fowls sickened much 

 sooner when fed on boiled rice than when the same variety of grain was 

 given unboiled. When they were given unhusked rice, or the so-called 

 red variety, no polyneuritis appeared; the sick ones could even be cured 

 by the latter. 



It then became of great importance to determine the difference between 

 white and red rice. No distinction can be detected between these two 

 varieties when they are unhusked, but it becomes apparent after they 

 have been husked. The grain (endosperm) in the red rice had re- 

 tained its pericarp (inner skin — Dutch, zilvervlies) , because there is great 

 coherence between the latter and the endosperm ; the pericarp contains a 

 red color in its component cells. Eed rice is commonly used as an article 

 of food for animals, and it is eaten by man only in some parts of 

 Java, therefore, no great labor is spent on removing the pericarp. The 

 pericarp must be totally removed to render the grain suitable for the 

 table (cleaned, or White rice), after which manipulation the endosperm 

 alone remains, that is, the grain then consists almost entirely of starch. 



These experiments prove that the husks are of no importance in the 

 etiology of polyneuritis. On the other hand, when the diet consists of 

 rice alone, the appearance of the disease depends upon whether the peri- 

 carp has been removed or not. Sick fowls recovered when fed on cleaned 

 rice, together with a quantity of the bran from the rice. 



Fowls fed on starch (cakes made of sago meal, pearl tapioca, or the 

 starch of the sugar palm tree 3 ) also suffered from polyneuritis, but they 

 soon recovered, exactly as fowls did which had fallen ill by being fed 

 on cleaned rice alone, when subsequently given raw meat. The disease 

 also appeared when the birds were fed on sago, tapioca or sugar palm 

 starch, together with a small quantity of meat; on the other hand, those 

 which secured potato-starch, or milk sugar with a small quantity of meat, 

 remained healthy. Polyneuritis never appeared when the fowls were 

 not especially fed. Pigeons contract the disease by being given the same 

 diet as fowls, whereas mammals do not. 



From the results of his experiments, Doctor Eykman concludes that 

 polyneuritis is caused by a poison present in starch or developed from 

 it, and that there are one or more constituents in the pericarp of rice 

 which counteract the poison, or prevent its formation. The same conclu- 

 sions hold with all varieties of rice ; neither its origin nor the time during 

 which it has been stored are of the slightest importance. 



•" Arenga saccharifera Labill. 



