White precipitate, or ammoniated mercurial ointment.—Useful in the case of head lice and several parasitic skin diseases.

Naso-pharyngeal Tablets.—Useful in nasal catarrh and pharyngitis.

* Opium.—Is a valuable drug, but it is also a poison, and great care should be observed in using it. Opium is narcotic and sedative in its action; it relieves pain of all kinds. Useful in diarrhœa, dysentery, cramp and colic. Promotes perspiration and checks vomiting. Sometimes it will cut short a cold or mitigate an attack of malaria.

No preparation containing opium should be given to children without medical advice, and the same is true as regards persons suffering from kidney disease.

The chief preparations containing opium are:—

* Chlorodyne.—The ordinary dose is ten to fifteen drops, but if there is great pain, then even thirty or forty drops may be given, but a second dose should not be administered for three or four hours; if two full doses have been given, do not give a third within at least twelve hours of the second dose, and do not give it at all if the patient is drowsy.

It is best not to give more than forty to sixty drops in twenty-four hours, unless there are very special reasons for giving a larger quantity. Is to be preferred to laudanum, as it is more palatable and more readily stops vomiting.

* Laudanum, or tincture of opium.—The doses and uses are precisely similar to those of chlorodyne. Laudanum has been put up in the compressed form, and is very convenient for transport.

* Dover’s powder, or compound ipecacuanha powder.—Dose five to fifteen grains. It contains opium and a small amount of ipecacuanha. Ten grains of Dover’s powder are equal to about fifteen drops of chlorodyne or laudanum. The tablet is an extremely handy preparation. Dover’s powder is especially useful in coughs and colds, the ipecacuanha it contains assisting the action of the opium. If a patient who is chilled is put to bed at once, kept warm with blankets and hot-water bottles, and is given ten or fifteen grains with a hot drink, he will perspire, and possibly the cold will be cut short.