The etiology of pellagra still awaits solution. Some there are who still talk of its infectious origin; others, in larger numbers, talk of dietary deficiencies, among which proteins and vitamines loom large. "Whatever the accepted hypothesis of causation may be," runs an editorial in the Journal of the American Medical Association, "there is no lack of evidence to indicate that the inclusion of a more liberal supply of good protein and sources of certain vitamines in the diet is likely to be beneficial in the case of pellagrins whose regimen almost invariably is deficient in the factors just emphasized."

Perhaps it will be best to quote one authority from each opposing camp.

A champion of the diet hypothesis, Dr. Voegtlin, of the U. S. Public Health Service, summarized, at a recent Harvey Society lecture, his views on the subject. No direct proof, he said, exists that pellagra has ever been transmitted experimentally to man or to animals. Direct proof supports the hypothesis that a causal relation exists between pellagra and a restricted vegetable diet. Diet is the essential factor in the treatment and prevention of this disease; an appropriate change in diet suffices as a preventive without any change in the sanitary conditions. A diet of the composition used by pellagrins prior to their attack by the disease produces malnutrition and certain pathological changes in animals, similar to those occurring in pellagra; however, typical pellagrous dermatitis (inflammation of the skin) has not been observed in animals. Continued consumption of a restricted vegetable diet has produced pellagrous symptoms in man. While the nature of the dietary defect has not been discovered, the observations point to a combined deficiency in some of the well recognized dietary factors.

A champion belonging to an opposing school is Dr. MacNeal, of the New York Post Graduate Medical School and Hospital. "In my own opinion," he writes, "the etiology of pellagra depends upon two factors: (1) The specific causative factor which is a living organism, an infectious agent derived directly or indirectly from a previous case of the disease; and (2) a factor or group of factors, quite non-specific, which serve to reduce the resistance of the victim. In this latter group are recognized malnutrition, either from inadequate food or inability to utilize food in an adequate manner. . . . The specific causative factor, which I believe to be a living organism, remains unrecognized. . . ."

An attempted reconciliation of the two schools of thought is the view of Dr. Viswalingam, which had its origin in a study of the etiology of the disease among the Chinese field laborers in the Malay States. The Malay and Tamil laborers are quite free from pellagra; this is attributed to the better quality of their diet, which includes fresh vegetables and some meat. However, faulty diet cannot be the sole offender, for there are seasonal recurrences of symptoms in patients placed in a hospital with adequate diets. "Whether the infecting agent is an organism which enters the gastrointestinal system and produces a toxin which gets absorbed into the system and produces the varied symptomatology, or whether owing to a deficiency in the vitamines some deleterious products are created in the intestines and give rise to an intoxication of the system, it is difficult to say at present."

If recent newspaper reports are to be believed, this year's death toll among the pellagra sufferers in the cotton districts of the South will reach 10,000. "A nation whose chewing gum bill mounts into millions of dollars can surely afford more than the meager sums voted by Congress for pellagra research and relief." Such is the very pertinent editorial comment in the Journal of the American Medical Association, (References: W. J. Macneal, Pellagra, American Journal of the Medical Sciences, volume 161, page 469, 1921; Editorial, Journal of the American Medical Association, volume 77, page 560, 1921; C. Voegtlin, Public Health Re-ports, volume 35, page 1435, 1920; Pellagra, Third Report of the Robert M. Thompson Pellagra Commission of the New York Post-Graduate Medical School and Hospital, 1917; J. Goldberger, Lancet, volume 2, page 41, 1920; A. D. Bigland, Lancet, volume 1, page 947, 1920; A. Viswalingam, Journal of Tropical Medicine and Hygiene, volume 23, page 46,1920; New York Times, July 25,1921; C. Voegtlin, H. M. Neill and A. Hunter, United States Public Health Service Hygienic Laboratory Bulletin, volume 116, page 7, 1920; C. Voegtlin and R. H. Harries, United States Public Health Service Hygienic Laboratory Bulletin, volume 116, page 73, 1920; J. I. Enright, Lancet, page 998, May 8, 1920; J. Goldberger, and G. A. Wheeler, Bulletin number 120, Hygienic Laboratory, Washington, 1920; E. V. McCollum, N. Simmonds and H. T. Parsons, Journal of Biological Chemistry, volume 38, page 113, 1919.)