It will thus be seen that there is convincing evidence that in wet beriberi, protein starvation is superimposed upon a deficiency of the anti-neuritic substance, water-soluble B. Wet beri-beri is a condition resulting from a double deficiency, whereas uncomplicated dry beri-beri would appear to be due to a single deficiency. This is, doubtless rarely the case, however, since the diet is so poor in quality with respect to several factors, wherever beri-beri occurs, that it can scarcely be regarded as a specific syndrome of an uncomplicated nature. It is this fact that explains the tendency of students of the diseases of dietary origin to emphasize the points of similarity of the two "deficiency" diseases, scurvy and beri-beri. Dilatation of the right side of the heart is reported for both scurvy and beri-beri in terms which leave little doubt that essentially the same condition is being described (35). Vedder (36) points out striking similarity in the nervous symptoms observed in scurvy, beri-beri and pellagra, and notes that there are certain resemblances in their symptomatology and pathology.

240. Two Or More Deficiency Diseases Doubtless Frequently Occur Together

In the light of the description which has been given of the dietary properties of our more important natural food-stuffs and the products manufactured from them, it is interesting and instructive to estimate the deficiencies of typical diets which have been described as having occasioned numbers of cases of the so-called deficiency diseases. Thus, in the Burma prison, there was an epidemic of scurvy with the following dietary (37):

In Southern Rhodesia, extensive epidemics of scurvy occurred in mines where the men were allowed the following foods (38):

Chamberlain (39) in 1910 observed that among 5,000 Philippine Scouts there were always from 100 to 600 incapacitated with beri-beri. Their diet had consisted of the following foods:

On changing the diet by substituting 16 ounces of unpolished rice and 1.6 ounces of beans for the twenty ounces of polished rice, and including 20 ounces of sweet potatoes, the number of cases of beri-beri had fallen off by the end of 1910, to fifty. The following year there were three cases; in 1912 but two, and no cases in 1913.