ETIOLOGY OF BERIBERI. 421 



periment it will be seen that the addition of iodine to the diet 

 of polished rice failed to prevent the development of polyneuritis, 

 whether added in organic or inorganic combination. 



Osborne and Mendel (3) in performing feeding experiments 

 with isolated food substances found that they could maintain life 

 on a diet in which the inorganic salts were supplied by Roh- 

 mann's salt mixture. It seemed, therefore, that, if fowls were 

 fed on polished rice and given this salt mixture and if polyneu- 

 ritis still developed, the inorganic salts could be finally excluded 

 from further consideration in the search for the neuritis- 

 preventing substance. 



Expeiirnent 27. — Rohmann's salt mixture was prepared as 

 follows : 



Constituent. 



Grams. 



Ca, (PO0 = 



10 



KjHPO* 



87 



NaCl 



20 



Sodium citrate 



15 



Magnesium citrate 



8 



Calcium lactate 



8 



Ferric citrate 



2 



Distilled water q. s. 



ad, 1,000 cubic centimeters. 



Four fowls were fed on polished rice and given an additional 

 daily dose of 10 cubic centimeters of this salt mixture. 



Three fowls developed neuritis in twenty-two, twenty-five, and 

 thirty-five days, respectively. 



Taking into consideration the large number of inorganic salts 

 which we have now tried with negative results as reported in 

 preceding papers, it seems evident that polyneuritis gallinarum 

 is not caused by the deficiency of an inorganic element in the diet. 



It has been suggested by several ^\Titers that polyneuritis 

 gallinarum is caused by the alcohol generated through the fer- 

 mentation of the excessive amount of starch. While not attach- 

 ing any importance to this speculation, it seemed desirable to 

 determine whether fowls would develop neuritis when given 

 considerable quantities of alcohol. 



Experiment 28. — Four fowls were fed on unpolished rice and 

 given a daily dose of 4 cubic centimeters of 95-per-cent alcohol 

 diluted to 10 cubic centimeters with distilled water. This was 

 continued for forty-five days when the experiment was inter- 

 rupted because it became necessary to leave Manila. No neuritis 

 had developed in any of these fowls, and they appeared to be 

 in good health although they had been receiving daily an amount 



