Before I proceed to the discussion of the special application of iodine, in a number of pathological conditions in animals, I would urge the veterinarian to give more thought to the forms and preparations of iodine of which he makes use. It is a rather common occurrence that a practitioner will allow agents of well-known therapeutic efficiency to be displaced, by others of doubtful activity, on account of a small difference in the cost of the same. This is especially true in the case of preparations in which the active ingredient, and, therefore, the ingredient to be depended upon for results, is iodine. Iodine, to begin with, as an elemental article, is costly. The veterinarian may, therefore, be sure that, whenever an iodine preparation, of a certain stated strength, is offered for sale at a price considerably lower than that of recognized preparations of a similar character, the lower price is possible only because of the fact that the iodine content is not as represented. In choosing preparations of iodine, for use in his practice, the veterinarian can easily deprive himself of much of the success that goes with correct iodine therapy, if he allows his choice of preparations to be influenced, to any great extent, by the cost of the article. This is the chief reason, and there is probably no other, why some veterinarians fail to get satisfactory results from topical iodine applications. They permit their better judgment, in the selection of the preparations, to be influenced too markedly by price; the preparation that they select fails to give the expected results because it is an inferior preparation, either in the strength or the quality of the iodine it is said to carry. Commonly, both strength and quality are inferior. Well made and honestly prepared iodine preparations are cheaper than almost anything that the veterinarian uses, in a pharmaceutical way; a little of a good iodine preparation “goes a long way”; and it accomplishes what it does solely through the exertion of its own energy. Almost never, it might be said, are other agents expected to assist it in its action. For this reason, it is very essential that the preparation be of correct and ample strength, that it contain the iodine in a form readily available by the tissues, and that the vehicle carrying the iodine have no detrimental action of its own.