The Relative Toxicity of the Halides and Certain Other Anions

When iodides are administered in ordinary doses excretion takes place rapidly. Heavy doses can usually be administered before toxic symptoms develop. The same is true to an even greater extent of bromides. The bromide ion appears to be capable of replacing the chloride ion to a Considerable degree in the body fluid of mammals without the production of distinct toxic symptoms. Thus Frey (1910--11) has shown that while administration of sodium bromide (to rabbits) leads at first to increased excretion of sodium chloride, if the relative amounts in the diet are kept constant bromide and chloride excretion become parallel; while an animal kept for some time on a deficient chloride diet, and then fed bromide, tends to retain bromide equally with chloride. There is evidence that some at any rate of the toxic symptoms following heavy administration of bromide are actually due to too great a depletion of chloride from the body, and not to the bromide ion (cf. Wolff and Opp, 1912). After bromide administration hydrobromic acid occurs in the gastric juice (Wolff and Opp). Similarly Herzfeld and Heimann (1911) have shown that after administration of iodide the excretion of chlorides and iodides is in inverse ratio. Hydriodic acid occurs in the gastric juice after iodide administration, and iodide is found in saliva, tears, perspiration, milk, sebum, and the secretion of the nasal mucous membrane (Cushny, 1918). I t is to be noted that Hale and Fishman (1908) state that bromide is excreted more slowly than corresponding doses of iodide.