Vedder71 points out that in the reports of cases which are supposed to discredit the dietary hypothesis the statements regarding the diet on which the disease has been developed are too vague to be of any value.

71 Vcdder, Am. J. Tropt. Dis. and Prev. Med. 1914, i, 826; Proc. 2nd Pan Am. Sci. Cong. Sect. 8, Pt. 2, p. 23.

"Any such communication to be worthy of attention should contain a detailed statement of the food actually consumed by the affected persons, for the 90 days prior to the development of the disease, showing components, quantities, and a statement as to whether the articles used were fresh, canned, or otherwise preserved".

While the antineuritic vitamin is so widely distributed that it is easy under ordinary circumstances to secure a diet which contains sufficient of it, there are times, - as in the rationing of armies in the field - when it is highly advantageous to have a concentrated supply. Where possible the use of whole meal flour from rye, wheat, or barley, or the liberal consumption of peas, beans, or lentils is recommended. Hulshoff72 reports from his study of the dietetic treatment of beriberi in the Dutch West Indies, that large amounts of puree of peas had an unmistakably curative action on beriberi. As much as 150 g. of the puree three times a day was required, however, smaller amounts showing no benefit. Oatmeal had a similar influence, but 125 g. three times a day was necessary. Europeans required a little less. A native bean seems also to have a like action. It is to be remembered that these substances lose their efficacy with age, three-year-old beans having been found quite inert.

Nuts in general are rich in antineuritic, and Grieg 73 recommends ground-nut (peanut) meal biscuit as emergency rations for the troops.

Commercial wheat germ is highly efficacious, being three or four times as potent as dried peas or egg yolk which come next in order. A preparation of yeast produced under special conditions according to researches carried out under the British War Office and known as "mannite " was used as an antineuritic by the British troops in Mesopotamia during the war and was found to be equivalent to wheat germ in efficacy.73a Autolyzed yeast is more effective than pressed or dried induced polyneuritis in pigeons by continuous feeding upon polished rice, and the therapeutic effects of various fractions of yeast were measured. What Abderhalden terms the "nutramine" of dried yeast can not be completely extracted by absolute alcohol, by acetone, or by a combination of these two extractives. The extracts of yeast given to pigeons on a rice diet ameliorate certain symptoms of the disturbance but they fail to provide a complete regimen. Apparently there is some substance, of an insoluble nature, in the yeast which is effective in combating the disturbances associated with a polished rice diet.

72 Pol, Norak. Mag. Laegevidenskaben 77, No. 1, 1916, J. Am. Med. Assoc. 66, 696.

73 Grieg, Ind. J. Med. Res. 6, 143, 1918.

73a Abdcrhalden (Arch. ges. Physiol. 178, 260, 1920).

Pigeons were fed for two weeks on a diet consisting exclusively of polished rice and at the end of this period they presented the characteristic manifest*yeast.74 Saleeby 75 prepared an extract of autolysed yeast by placing brewers' yeast, separated from the adhering beer, in an incubator at 35° C. for about 48 hours, filtering, and concentrating the filtrate under reduced pressure at a temperature below 60° C. to about one-third of the original volume. About 40 cases of beriberi (five of them children under two years) were treated with this extract, adults being given 15 to 40 cc. three times a day, children two to four cc. every three hours. All acute symptoms of neuritis were affected in less than three days. Infantile symptoms were cured with comparative rapidity. Hydrolyzed extract of rice polishings produce a similar and even more pronounced effect.76 tions of alimentary dystrophy. During the period of the experiment, body weight, temperature and gas metabolism determinations were made and curves which were plotted for the values secured show a gradual fall throughout the course of the experiment.

When yeast, or an alcoholic extract of yeast, was added to the diet, a rise in the gas metabolism always occurred. (Arch, ges Physiol. 1021, 80).

74 Seidell, J. Biol. Chem. 29, 145, 1918.

75 Saleeby, Phil. J. Sci. 14, 11, 1919.

76 For preparation of concentrated vitamin extracts see Ch. VII.

Simonnet (Bull. soc. hyg. 9, 09, 1921) presents data obtained in feeding experiments with pigeons. The "complete diet" used consisted of the following: Meat residue 11 g., peanut oil 5 g., potato starch 69 g., salt mixture 4 g., filter paper 5 g., agar 5 g., butter 10 g., brewers' yeast 1 g. The butter furnished A, whereas the yeast was the only source of B and C. This diet permitted satisfactory maintenance of the birds during the experimental period of 170 days. The same ration but without yeast did not permit maintenance of the birds. Characteristic symptoms of polyneuritis appeared.

The respiratory quotient was studied by Jansen and Mangkoewinoto (Med. geneesk. lab. Weltevreden [Java] 1920, 3e Ser. A, Nos. 1, 2 and 3, 60; Physiol. Abe. 5, 901; Chem. Abs. 1921, 2606) with the hope that the fall in, respiratory quotient might be made use of in testing foods for antaneuritic vitamin. The respiratory quotient did fall in one or two cases, but the fall is not constant and reliance cannot be placed on it in the diagnosis of polyneuritis.

When fowls and cats were fed on polished rice and food deficient in vitamins, the organs did not show any change in sensitivity towards adrenaline, histamine, choline, and atropine. (Van Leeuwen and Verzar, Chem. Abs. 1921, 2658).

Fitch (Am. Med. 16, 969, 1921) reports a series of experiments in which beriberi was produced in pigeons by feeding polished rice.