The literature bearing on the toxicity of zinc to the animal body is very confused. D\u27Amore, Falcone, and Marmaldi (1) fed zinc oxide to dogs; they called attention to the loss of appetite and the weak condition of their animals with the further observation that the blood color and the number of red cells were greatly diminished. During the last days of the poisoning, the white cells markedly increased. Urine of the dogs was diminished in volume and contained casts and albumin. Lehmann (2) fed zinc carbonate to dogs for eleven months with no evidence of poisoning. Batchelor, Fehnel, Thompson, and Drinker (3) observed no anemia from administration of zinc. More recent studies have been made by Heller and Burke (4) and Myers, Beard and Broda (5). The latter investigators (5) fed adult rats zinc chloride to the extent of one per cent of zinc and observed that, while the body weight remained constant, the hemoglobin was reduced from 14.3 to 11.1 grams per cent; but the red cells did not change in number. Myers and Beard (6) also found, when zinc chloride was used to supplement iron chloride in blood regeneration, that more than one-tenth of a milligram of zinc daily prolonged the time necessary for the blood to be restored to normal. Keil and Nelson (7) fed two-tenths of a milligram of zinc as zinc chloride daily to rats, without any effect upon the rate of development of anemia
