MINERAL OE INOEGANIC POISONS 89 



bromine, since many substances — e.g., nitrous fumes and 

 hydrogen peroxide — also liberate iodine from iodides. 



When given internally bromine is very poisonous. Ac- 

 cording to Law, 120 grains killed a dog in five hours ; 10 

 to 12 drops in an ounce of water intravenously proved sud- 

 denly fatal (Orfila). Iodine in doses of 5 to 6 drachms by 

 the mouth killed dogs in a few days (Orfila), a half-ounce of 

 iodine caused colic in a horse (Tabourin), and 2 drachms 

 intravenously killed (Patu). Hertwig gave horses 40 to 60 

 grains of iodine twice daily for fourteen days, without 

 causing death, and larger doses of several ounces have 

 failed to injure cattle. 



Very large doses of these agents cause acute abdominal 

 pain, diarrhoea, which has the bromine or iodine odour, 

 general weakness, vertigo, and convulsions. 



lodism, following protracted administration of full doses, 

 is marked by catarrh of the nostrils, throat, and alimentary 

 organs, suppressed urination, weakness, emaciation, scaly 

 skin eruptions, and the hair falls off in patches. 



Boiled starch is recommended as an antidote in fixing 

 free iodine, but is of doubtful value, and certainly useless, 

 apart from its demulcent effect, for bromine. 



Bromides of sodium and potassium, which closely resemble 

 common salt in appearance, are more dangerous than it 

 (see Common Salt). But the doses required to exercise 

 toxic effects are very large, and not likely to be the cause 

 of accidental poisoning. There is so great a difference in 

 the cost of the iodides and bromides as compared with 

 chlorides that risk of substitution of them for chloride is 

 very greatly minimised. One ounce of bromide to a horse 

 causes listlessness, muscular feebleness, unsteadiness of 

 gait, impaired reflex movements ; the pulse is feeble, res- 

 piration slowed, rectal and cutaneous temperatures are 

 diminished, and secretion of urine increased. Dogs display 

 similar symptoms after 45 grains (Finlay Dun). The 

 vomition, diarrhoea, and diuresis are general effects of 

 salt administration. 

 Bromism, with cerebral depression, increased secretion, 



