Probably the most important conditions to consider in differentiation of beriberi are the peripheral nerve involvements caused by alcohol and arsenic. In alcoholic neuritis there is the history of alcoholic excesses, long-standing digestive disorders and tremors of hands, lips and tongue. Chiefly characteristic, however, is the mental involvement, such cases almost always showing loss of memory and defective mental concentration. Mental symptoms and tremors are practically absent in beriberi and we have here the marked feature of vagal involvement plus vasomotor phenomena. In arsenical neuritis we have an early puffiness under the eyelids and pigmentation of the skin which first shows itself in areas normally pigmented. A dysenteric syndrome may also be present. There would be less chance of confusing lead palsy as this chiefly involves the upper extremity. Punctate basophilia, lead colic and the blue line on the gums should differentiate. In diphtheritic palsies the muscles of the soft palate are involved in more than 75% of cases. Ocular palsies are also not infrequent. In lathyrism we have a history of the eating of the chick-pea (Lathyrus sativus) or other vetches, as may occur in times of famine. Pain in the back, weakness of the legs and symptoms of spastic paraplegia appear. The spasticity differentiates. The heart is not affected. It may be stated that there is no laboratory diagnosis for beriberi. PROGNOSIS There is no disease in which one should be more conservative in making a favorable prognosis than in beriberi. A case which seems to be progressing toward recovery may suddenly develop cardiac disturbances and die in a very short time. We now know that a change to a beriberi-preventing diet is practically curative. The mortality rate varies in different countries and in different epidemics, so that we have death rates varying from less than 2 per cent. to those exceeding 50 per cent. In acute pernicious beriberi the prognosis is almost surely fatal. The epidemic of beriberi which prevailed at Manila in 1882 seems to have been attended by a great mortality, this having been as high as 60% during the early part of the outbreak. PROPHYLAXIS AND TREATMENT =Prophylaxis.=—It must be remembered that not only is rice, from which the neuritis-preventing vitamine has been removed by excessive milling, productive of beriberi but that the same applies to other cereals which have been similarly deprived of their vitamines. The same result may be obtained by the employment of excessive sterilization for canning. Fresh meat is as valuable as fresh vegetables in prophylaxis but if either kind of food be subjected to excessive heat, as is the case with tinned meats, etc., they not only do not prevent beriberi but in a negative way are beriberi-producing.