182 The Philippine Journal of Science im 



Four fowls were fed on polished rice, and were given a daily 

 dose of 10 cubic centimeters of this solution. One fowl developed 

 neuritis in thirty-five days, one in thirty-seven days, and one in 

 forty-five days, when the experiment was discontinued. It 

 appears from this experiment that the fowls may have received 

 some protection, since the incubation period was somewhat pro- 

 longed. (Average incubation period of our experiments twenty- 

 six days.) The protection afi'orded was but slight. 



The explanation of the failure completely to protect these fowls 

 undoubtedly lies in the fact that sufficient amounts of this base 

 were not used. In the curative experiments relatively large 

 quantities of this base were used ; that is, 30 milligrams. Funk 

 obtained only 0.4 gram of this base from 50 kilograms of polish- 

 ings, and the amounts we have obtained from several hundred 

 kilograms of polishings have been proportionately even smaller. 

 It is, therefore, apparent that to cure one fowl a quantity of 

 the base extracted from about 5 kilograms of polishings was 

 used, or almost five times the total quantity used to feed 4 fowls. 

 But if this base were the only protective substance contained 

 in the rice polishings, and were completely extracted, it is evi- 

 dent that the equivalent of 10 grams of polishings should have 

 fully protected. Since this quantity did not protect completely 

 in a feeding experiment, we now considered the following 

 possibilities : 



1. That there are other protective, if not curative, substances 

 in the polishings besides Funk's base. 



2. That Funk's base is incompletely extracted by Funk's 

 method. 



3. That both of the above hypotheses are correct. 

 Experiment 45. — An extract of rice polishings was prepared 



according to our usual method and without hydrolysis was pre- 

 cipitated by phosphotungstic acid. The washed precipitate was 

 then mixed with distilled water in such proportion that 10 cubic 

 centimeters of the suspension represented the substances pre- 

 cipitated by phosphotungstic acid from 10 grams of polishings. 

 Four fowls were then fed on polished rice, and were given a 

 daily dose of 10 cubic centimeters of this suspension. One fowl 

 died of avian diphtheria after fifty-one days, and the other 3 

 birds remained in perfect health for seventy-one days, when 

 the experiment was discontinued. This experiment showed 

 that the total phosphotungstates precipitated from an unhy- 

 drolyzed extract of rice polishings were sufficient to prevent 

 polyneuritis in a dosage corresponding to 10 grams of polishings. 



