In prescribing this medicine, it is very necessary not to lose sight of the effect I have just mentioned. When the tumor is very large, and especially in that kind of bronchocele, in which the principal enlargement of the thyroid gland takes place on its inner surface, where it is in contact with the trachea, the occurrence of inflammation is much to be apprehended. When a very large tumor becomes inflamed, the distress which it occasions, and the disturbance it excites in the constitution, are very considerable; and in the second case to which I have alluded, inflammation of the trachea is very readily excited.[5] Such cases are easily distinguished by the immovability of the tumor, and the effect they have in altering the voice. On dissection, the trachea is sometimes found to have been very much compressed by them. [5] Dr. Coindet gives an instructive example of this kind. _Bibliothèque Universelle, Février, 1821_, p. 148. It is now fit that I should mention the most common and beneficial methods of using this substance. Dr. Coindet has recommended the hydriodate of potass as an external application, and my experience has certainly confirmed his choice. The hydriodate of soda, however, will be found to answer equally well. Practitioners may choose between these two remedies. I have used the iodates, but I have found them at once more inert and more unmanageable. They possess all the virtues of iodine in a very remarkable degree, but they will be found to fail more frequently than the hydriodatic salts; and, if I may draw any conclusion from the few trials I have given them, they are more apt to excite disorder in the system. I have generally ordered half a dram of the hydriodate of potass to be united to an ounce and a half of axunge, and desired the patient to rub in a dram of this ointment over the surface of the tumor, night and morning. When the tumor is painful, it is not necessary to rub in. The ointment may be used in the manner recommended by Scattigna.[6] All that is necessary is to choose a portion of the surface of the body where the skin is very tender and thin, and simply to apply the ointment over night. For this purpose, almost any part of the body which is habitually covered may be chosen; but in the axilla, and in the inner surface of the thighs close to the scrotum, the absorption will be found most rapid.[7] [6] Nuovo metodo di amministratori l’unguento mercuriale ne mali fisici del Dottore Vitantonio Scattigna. Napoli, 1818.