Essay on the effects of iodine on the human constitution / With practical observation on its use in the cure of bronchocele, scrophula, and the tuberculous diseases of the chest and abdomen

I have here thrown into an Appendix a brief account of the different preparations of which I have had occasion to make mention. It is chiefly extracted from Magendie’s Formulary, which will be found to contain sufficient directions for the chemical and pharmaceutical operations undergone by iodine.

This preparation should not be long kept, as it readily undergoes alteration and decomposition. Alcohol varies in its solvent power of iodine according to its degree of concentration. The frequent opening of the vessels, therefore, in which it is kept, must occasion a change in the quality of the tincture, by allowing the evaporation of the spirit, and thus occasioning a diffusion of undissolved iodine through this preparation. Mr. Magendie seems also to fear, that a decomposition of the alcohol may take place from the superior affinity of iodine for hydrogen. Altogether this is certainly the most objectionable form in which iodine is used.

I have generally prescribed these two preparations in cinnamon or mint water, in which form they are seldom disagreeable to the stomach. I have avoided, as much as possible, joining them to any tinctures or infusions, as we are yet in a great degree unacquainted with the chemical habits of iodine and the different vegetable substances. It will be sometimes, however, found advisable to use tonics with iodine.