Deficiency of ivhich causes Beri-heri in Man. 47 



to see the swift dramatic changes (in 6-24 hours) so typical of the cure of 

 polyneuritis in birds, when the vitamine is administered in a soluble form. 

 ISTevertheless, with the exception of a small proportion of cases, where the 

 character of the symptoms and the general condition were unsuitable, cures 

 can usually be accomplished if the amount of vitamine given is adequate. 

 Some examples are given in Tables V and VI below, in which similar material 

 was used for cures both before and after concentration of the active substance 

 by extraction. In the case of wheat germ, the curative dose was found to be 

 equal to 2'5 grm. of the original material ; after extraction, the equivalent of 

 15 grm. was required, which result shows the large proportion of vitamine 

 lost by the extraction process. 



In the case of comparative curative experiments the difficulty is, firstly, 

 to form a judgment of the severity of the symptoms, and, secondly, to obtain 

 a sufficiency of acute cases in which this shall be approximately equal. This 

 difficulty was not altogether overcome, as will be seen in the somewhat 

 irregular results of the experiments described below, especially those set 

 forth in Table VI. Preventive experiments form the more satisfactory 

 method of estimating the vitamine-content in foodstuffs and yield much 

 more regular results. The drawback is that they take at least two months 

 to complete, and, if adopted exclusively, would limit the scope of any 

 enquiry. 



Feeding was artificial in both cases and the rice rations given in the Tables 

 must be regarded as approximate only, since the birds frequently vomited 

 small amounts after feeding. In case of the wheat-bran and wheat-germ 

 rations, no significant amount of vomiting was noticed, nor was the rice 

 vomited when these substances were added to the diet. 



Wheat Embryo. — Tables I and II give the results of preventive experi- 

 ments with two different samples of wheat germ, and in each case a series 

 of birds was arranged to act as control, with a diet consisting exclusively 

 of polished rice. The results of these two sets of experiments are in con- 

 cordance ; in both a ration of 3 grm. wheat germ, given every second day, 

 "was found to afford complete protection from polyneuritis. With 2 grm. 

 every second day, half the birds used in each experiment were protected. 



Wheat Bran. — The wheat bran used for comparison with the wheat germ 

 was what is known as " Broad bran," and the sample E.I. (Table III) was 

 obtained from the same wheat as germ E.I. (Table II) and white flour E.I. 

 (Table IV). It consisted of large particles, and in its thickness comprised 

 all the outer layers of the grain. Traces of the starchy endosperm were 

 visible iipon the inside surface, and the presence of the aleurone-layer was 

 demonstrated by sections. The sample K.I. was obtained from a modern 



