98 THE VITAMINS 



these two results before any satisfactory conclusion on this point can 

 be drawn." 



In experiments designed to determine the antineuritic values of 

 foods by finding the amounts required to protect pigeons or fowls 

 from polyneuritis, it has been common to use polished rice as the 

 basal diet, although this plainly does not meet the desideratum of being 

 nutritionally adequate in all respects other than the vitamin under 

 investigation. 



In order that all other nutritional needs should be adequately met, 

 Simonnet (1920) proposed the use of the following ration for the 

 study of polyneuritis in pigeons : 



Meat residue prepared by double extraction with boiling alcohol and 

 ether 11 grams, Osborne and Mendel's salt mixture 4, pulverized agar 5, 

 peanut oil heated for 3 hours at 130° C. 5, cellulose 5, butter melted, 

 decanted and filtered at a temperature below 40° C. 10, and potato starch 

 60 grams. These ingredients are intimately mixed with 80 per cent of 

 their weight of water and made into pellets, which are introduced into 

 the crops of the experimental pigeons in two daily doses and in amounts 

 equal to one-fifth of the weight of the bird. The pigeons are kept in 

 very large cages to allow considerable freedom. 



On the above diet the pigeons are said to maintain their weight 

 but to develop a form of avian polyneuritis unaccompanied by paralytic 

 and atrophic symptoms, in the development of which inanition and 

 multiple deficiencies are considered to play the important role. The 

 disease appears generally in about 30 days, and is usually fatal in 4 

 days if no treatment is given. The administration of dry or autolyzed 

 yeast brings about prompt recovery. By supplementing the deficient 

 ration by the administration of 0.5 gram of dried yeast daily, the 

 pigeons can be maintained in excellent health for more than 7 months. 



Experiments with pigeons using weight-maintenance as a criterion 

 for the antineuritic potency of a product must now be questioned, for 

 recent work of Williams and Waterman (1928) and Randoin and 

 Lecoq (1928) indicate that at least two factors are here involved 

 (vitamins Bi and B3). 



Slight modifications of the Simonnet ration (Lopez-Lomba and 

 Randoin, 1923a; Randoin and Simonnet, 1923), and others of the 

 same type (Gulick, 1922; Hoet, 1923), have since been described and 

 have been used particularly in certain studies of the physiological role 

 of vitamin B. 



Most investigators have, however, inclined to the use of the growing 

 rat as a means of testing foodstuffs for their vitamin B values. 



