44 Miss H. Chick and Miss E. M. Hume. The Substance, the 



easily hydrolyses into its component mononucleotides, but the latter is 

 comparatively stable. Evidently a similar decomposition of nucleic acid has 

 taken place during peat formation, and the relatively unstable guanine- 

 cytosine dinucleotide has been further decomposed into its constituent parts. 



In view of the stable nature of this adenine-uracil dinucleotide and the ease 

 with which it can be extracted from peat, it is surprising that its occurrence 

 as such in nature has hitherto escaped observation. 



So far the work has been purely qualitative, but a more exhaustive 

 examination of the substances obtained is now in progress, to determine not 

 only the quantitative proportions of the various radicles, but also their 

 elementary composition. 



The Distributio7b in Wheat, Rice, and Maize Grains of the 

 Substance, the Deficiency of which in a Diet causes Poly- ■ 

 neuritis in Birds and Beri-beri in Man. 



By Harrietts Chick and E. Margaret Hume. 



(Communicated by Dr. C. J. Martin, F.E.S. Received January 10, 1917.) 



(From the Listei' Institute.) 



Our attention was turned to this subject by the reported occurrence of 

 beri-beri among our forces in the Dardanelles and Mesopotamia during the 

 autumn and winter of 1915 (see Wilcox, 1916, I and II). Owing to the 

 exigencies of the military situation, many individuals in these regions subsisted 

 for considerable periods mainly on tinned meat, jam and white bread (or 

 biscuit baked principally from white flour)'. Beri-beri has in recent years 

 been included among the deficiency diseases, and there was therefore good 

 presumptive evidence that the diet had been at fault. We examined two 

 samples of tinned meat-and-vegetable ration by the methods described below, 

 and found, as was to be expected, that the substances preventing beri-beri 

 in the fresh materials had not survived the heat-sterilisation undergone in the 

 process of canning. The case of bread and biscuit demanded a more extended 

 investigation, and the present work is concerned with the nutritive properties 

 of cereals generally, especially wheat. 



One member of this group, viz., rice, has been exhaustively studied in 

 recent years, and the work, among others, of Eijkman, Grijns, and Braddon 

 has established the etiology of tropical beri-beri in a deficiency in the diet of 



