284
ELEMENTS OF MATERIA MEDICA.
conjunction with iodine, forming what is called iodurctted iodide ofpotassium.
1. Of Iodidf. of Potassium .— Internally it has been given indoses varying from three grains to half an ounce (see p. 283). Tobe beneficial, some think it should be given in small, others in largedoses. Not having had any experience of the effects of the enormousdoses before referred to, I can offer no opinion thereon. It may beadministered dissolved in simple or medicated water, or in some bitterinfusion. The more usual mode of exhibiting it is in combination withiodine, in the way presently to be noticed.
For external application iodide of potassium is used in the form ofointment. The unguentum potasses hydriodatis of the Dublin Pharma-copoeia consists of a scruple of iodide to an ounce of lard; but for ordi-nary purposes it should contain at least a drachm of iodide. By keeping,it undergoes decomposition and acquires a yellow colour, a little iodinebeing set free. It bas an advantage over the compound iodine ointmentof the London Pharmacopoeia, that it does not stain the skin.
2. Of Ioduretted Iodide of Potassium .— A solution of iodideof potassium readily dissolves free iodine, and the compound is usuallytermed ioduretted iodide of potassium. Iodine and iodide of potassiumare also used together in the form of ointment.
For internal administration there are three preparations of iodurettediodide of potassium which have been employed: the ioduretted mineralwater of Lugol; the compound solution of iodide of potassium of theLondon Pharmacopoeia; and the compound tincture of iodine of the samework.
[a) Ioduretted mineral water. —This is Lugol’s favourite preparation.He uses it of three different degrees of strength.
No. 1.
No. 2.
No. 3.
Iodine.
■ gr. L • •
H
Iodide of Potassium .
. gr. 4. . .
Distilled Water ....
. S viii . . .
• ■ 3 viii . . .
The solutions are yellowish or orange coloured, and are quite trans-parent. When sweetened it is readily taken by children, but the sugarshould be added at the time of administration, as in the course of a fewhours it effects a chemical change in the solution. From six to eightounces should be taken daily.
(5.) Compound solution of iodide of potassium. —The liquor potassniodidi compositus of the London Pharmacopoeia consists of:—
It is a brown coloured solution, and may be usefully employed in thediseases of children. Dose for adults from two to six or more fluidrachms.
(c.) Compound tincture of iodine .—The tinctura iodinii composila ofthe London Pharmacopoeia consists of:—
Iodine.t j.
Iodide of Potassium ^ ii.
Rectified Spirit.. O ii.