Used externally, it acts as a counter-irritant, and should not be painted on too freely as it may cause blistering. Does good if painted over swollen joints or enlarged glands, but should not be applied if the skin there is broken. Tincture of iodine may be painted on the chest or over the liver or spleen if there is pain. It is a valuable application for all open, recent wounds, and may be painted freely over and round the raw surface. It relieves the irritation of mosquito bites.
Is very useful in certain diseases of the skin, such as ringworm, kraw kraw, and dhobie itch.
Iodoform powder is a valuable antiseptic, and is used for all kinds of sores, or wounds, in which it rapidly promotes healing. One part of iodoform to eight parts of vaseline makes a good healing ointment.
| Ipecacuanha.—Dose, | expectorant, | half to two grains. |
| ” | emetic, | fifteen to thirty grains. |
| ” | for dysentery, | twenty to forty grains or more. |
In small doses, e.g., a quarter to half a grain, is a stomachic and may check vomiting.
Was formerly much used in amœbic dysentery ([p. 187]). Its active principle, emetine, is now employed.
By causing free expectoration, it is very useful in bronchitis, and is then usually combined with ammonia.
Is contained in Dover’s powder, and in this form is useful in coughs and colds, as it helps to cause sweating.
Iron.—Iron is much used on account of its tonic and blood-forming properties. It is especially useful in anæmia following fevers and other exhausting diseases, and it also gives tone to the nervous system.