51 



other hand yeast raises tlie vitamin-coiiteiit ; it has a protective and 

 curative effect ^^ ith respect to polyneuritis. An accidental advantafi,e is 

 that during the baking the internal temperature of the dough hardly rises 

 above 100° C As has been shown l\y Ghijns for rice and lias been 

 corroborated also by myself for other cereals, vitamins are destroyed 

 by moist heat only at much higher temperatures. 



In the writer's laboratory two sets of three fowls have been 

 subjected by Dr. Hullshoff Pol to feeding-experimenis on brown- 

 and white-bread ; they were young, strong animals of about the 

 same age (± 2 years) and weight. Tl\e best fed animals were taken 

 for the white-bread experiment; their body-weight averaged ca. 

 1550 grms; that of the brown-bread fowls was ca. 1400 grms. The 

 bread-ration was ca. 100 grms. 



The results of the experiments are given in the graphics. S denotes 

 the moment when forced feedi-ng commenced. P that when the 

 typical symptoms of polyneuritis (disturbances in the gait) made 

 their appearance. For purposes of accurate comparison the changes 

 in the body-weight are not expressed in absolute measure, but in 

 percentages of the initial body-weight. 



When first studying the whitebread experiments, we shall notice 

 a fall in the body-weight almost immediately, in spite of normal 

 appetite, which fall continued also after we proceeded to forced 

 feeding. At the close of the 11'^' week the first fowl (III) devel- 

 oped polyneuritis and succumbed after a few days. A second (II) 

 followed a week later. Henceforth it was fed on brown-bread, just 

 as N". I, which had lost flesh, indeed, but was not yet actually ill. 

 With this diet the diseased animal recuperated and the fall in 

 body-weight was arrested in either of them. 



Whereas with a polished-rice diet the fowls develop polyneuritis 

 most often inside of five weeks, not unfrequently even as early 

 as at the end of the 3'^ week, this outbreak was considerably retard- 

 ed in the case of fowls on white-bread. It seems probable that 

 this is due to a protective action of the baker's yeast. 



Much more favourable were the results of the brown-bread ex- 

 periments. N". IV and V remained perfectly healthy and vigorous 

 up to the conclusion of the experiment, which lasted 20 weeks. 

 They increased in body-weight, N". V even considerably, so that 

 there was no occassion for forced feeding, although a slight inap- 

 petence ensued, as is always the case with a uniform diet. 



N". VI fared worse. For the first fortnight it maijitained its 



original weight, but after this time it lost weight constantly ; forced 



4* 



