IODINE.

121

Before noticing these, however, it may not be amiss to mention thatwith the view of preventing gastric irritation, we should avoid givingiodine on an empty stomach. If administered immediately after a mealthe topical action of this substance is considerably diminished. This isespecially the case if potatoes, bread-pudding, sago, tapioca, or otheramylaceous substances, have been taken, since an iodide of starch (whichpossesses very, slight local influence) is immediately formed in thestomach.

{a.) In substance, iodine has been given in the form of pills, in dosesof half a grain, gradually increased. But this mode of exhibition is nowrarely resorted to.

(b.) Tincture of iodine. —This is a simple solution of iodine in rectifiedspirit, and may he made of various strengths. In the Dublin Pharmaco-poeia the proportions are two scruples of iodine to one ounce (by weight)of spirit. It is, however, an objectionable preparation: for, in the firstplace, by keeping, part of the iodine is deposited in a crystalline form, sothat the strength is apt to vary ; secondly, it undergoes decomposition,especially when exposed to solar light; the iodine abstracts hydrogenfrom the spirit, and forms hydriodic acid, which, acting on some spirit,forms a little hydriodic ether. These are not the only objections: whenadded to water, the iodine is deposited in a solid state, and may thusirritate the stomach. It is used both externally and internally : exter-nally it may he mixed with the soap liniment, and internally it is exhi-bited in doses of from five or six drops to half a drachm. Each drachmcontains live grains of iodine. The best mode of exhibiting it, to coverits flavour, is in sherry wine. Where this is inadmissible, sugared watermay be employed.

(c.) Combined ivith starch, iodine has been given in enormous quantitiesby Dr. Buchanan ( Med Gaz. vol. xviii. p. 515.) His formula for mak-ing the iodide of starch is the following :—“ Rub 24 grs. of iodine with alittle water, and gradually add one ounce of finely-powdered starch : dryby a gentle heat, and preserve the powder in a well-stoppered vessel.”In persons not labouring under any dyspeptic ailment or constitutionaldelicacy of habit, Dr. Buchanan commences with half an ounce for adose, and increases this to an ounce three times a day,—equivalent to 72grains daily. It frequently caused costiveness, attended with gripingpains of the bowels and pale-coloured evacuation. In some cases, butrarely, it produced purging. Though starch diminishes or nearly destroysthe irritant properties of iodine the prudent practitioner will commencewith small doses, (5ss.), of the iodide, and carefully watch the effect ofgradually and cautiously increased doses. I have found the colour ofthis preparation objected to by patients.

((/.) Combined with hydrogen, forming hydriodic acid, Dr. Buchanan{op. cit.) has given iodine in very large quantities. His formula for mak-ing this acid is the following:—“ Dissolve 264 grs. of tartaric acid in 1|ounces of distilled water, and to this add a solution of 330 grs. of iodideof potassium also dissolved in 1 ounces of distilled water. When thebitartrate of potash has subsided, strain, and, to the strained liquor, addsufficient water to make fifty drachms (Svj. 3 ij.) of solution.” Of thissolution Dr. Buchanan has given as much as an ounce three times a day,or two drachms of iodine daily: and he regards half an ounce as the