The liability of iodine to excite great disturbance in the constitution, has been made an objection to its use. I fear that this reproach must be shared by all powerful medicines whatever. If unattended to, or used with levity, any medicine which is capable of doing good, may also do harm. But if used with due discretion and properly watched, I have no hesitation in affirming, that iodine may be employed with as much safety as any of the powerful remedies which are daily in the hands of the least skilful members of the profession. But it has been also made a subject of reproach to this remedy that it is quite inert and useless. I shall not give any further reply to such a statement than what the foregoing pages contain. But I am credibly informed that it has been used by several eminent practitioners of London; who finding it quite inert, had laid it aside as useless[10]. [10] So great have been the ravages committed by the imprudent use of iodine in the Pays de Vaud, that the government of that canton has issued an injunction against its sale, excepting under the signature and responsibility of a physician. I have already pointed out one source of such mistakes (page 3). I fear, however, that it has also been used by physicians who have not leisure of mind nor time enough for conducting such inquiries as they ought to be conducted. When we consider the silly pretences on which medicines are sometimes forced into fashionable practice, it will not appear wonderful that the investigation of their virtues should not be conducted with much zeal. But I know also that it has been hastily rejected, and without trial, by some persons grown old in the practice of physic, who have made their interests decidedly to consist in defending all that is old, and repudiating all that is new. Such persons expose themselves to ridicule when we see them reject a remedy so active as iodine, and continue to trust, for the cure of the severest diseases to which the human frame is liable, to medicines allowed on all hands, and even by themselves, to be absolutely useless. The value of iodine as a remedy, however, does not depend on the testimony of any individual, however high his name. Its use is established by a long series of facts observed by physicians and surgeons of different countries. Wherever it has received a fair trial from unprejudiced persons, its effects have been so striking and undeniable as to force assent. It is not one of those remedies which is adopted by one man, and rejected by another, according to the accident or caprice of the moment; but one whose effects are written in such clear and intelligible characters, that _he that runs can read_. Its applications also are in cases of such common occurrence, that all practitioners have an opportunity of satisfying themselves of the real nature of the remedy, and the extent of its powers.