DIETKTIC I)KFI(TKXtY. 30I 



of polished rice per day an attack is usually developed in about 

 three weeks. 



(2) Chronic Form. — The l)ird sits motionless in its cage, and 

 seldom moves unless comjielled to. Finally the locomotor ftinc- 

 tions may even be entireK' lost. This form is not so easil\' dis- 

 tinguished as the fu'st. 



Associated with both forms is a marked drop in weight — 

 the more marked, the longer the l)ird survives. In acttte cas-:i 

 coming on early the drop may only W lo ])er cent, or so. !•' 

 chronic cases it nia\- l)e as high as 50 ])er cent. In both f onr. ■: 

 death ensues if rigid adh.erence to the causal vitamine-])oor die^. 

 is observed. 



Evkman recentl\ ( igr_-;) stated that he had observed reco- 

 verv in pigeons after the injection of the mixed chlorides of 

 sodium and potassium, but as we om'selves have observed similar 

 temporary recovery following the injection of water, we consider 

 such recovery to be spontaneous. 



Both forms are curable by sim])le administration of vitamine 

 extracts either per os or subcutaneousK'. and it the bird shows 

 temporary s|)ontaneous recovery it ma}- be ra])idly restored to 

 complete health and original weight bv change of diet to food- 

 stuffs rich in vitamine. The acute form is most easilv cured, and 

 in an astonishingly short time. A bird ma\' l)e on the verge of 

 death and yet be restored to apparently healtln- condition with'ii 

 a few hours by the injection of vitamine extract. 



In birds the nervous degeneration observed after death from 

 beriberi is usuallv ver}- characteristic. 



Chemical Naliire of Ihe Curative or Preventive Substances. — 

 To Eykman ( iHc)- ) belongs the credit of the pioneer work. He 

 found that the rice polishings.or ])ericarp and subi)ericar|)al layers 

 of the grain. ])()ssessed the ])ower of ])reventing the outbreak of 

 polyneuritis in birds fed upon polished lice. He, however, ex- 

 ])lained his results on the sup]iosition that a to.xin was develo])ed 

 from the starch of the grain which actefl injurioush- on the ner- 

 vous system, and that the toxin action was ])revented bv some 

 antitoxic body present in the pericarp. 



Eykman also observed ( 1906) that an aipieons extract of 

 rice polishings possessed ctirative pro])erties. 



Frazer and Stanton showed t'at the active curative ])rincii)lc 

 of rice polishings was solul)le in :il.:oliol, :in(! '-cmained in solu- 

 tion after all ])roteins were ])recipitated. The\- carried out analyses 

 of different samples of rice, and showed that a certain em])irical 

 relationshi]) existed between the ])hos])h()rus content and the 

 curative constituent, suggesting an indicator limit of 0.4 per cent. 

 P^O-. Rice containing more than this amount of phos])horus 

 was regarded by them as safe f( r sole consum])tion. without 

 danger of beriberi. 



About the same lime (iryns contirmed l^ykman's earlier 

 work, and suggested that the cause of the disease was delicienc^ 

 of some substance necessarv for nerve metal)olism. Me also 



