fail to perceive; and the fact is so clear to reason, that it is not disproved, because it hitherto has not been rendered plain to the vision. Neither does it invalidate my conclusion to adduce instances where the horse had been observed to exhibit no affection subsequent to the use of these medicines. The negative can establish nothing. The cause has not been suspected, and the effect, of course, has not yet been observed; but we abuse our reason, if we refuse to listen to its teachings. I am not likely to have met with the proof it may be desirable I should adduce; for perceiving the evil I early forbore, to render possible any evidence of its tendency in my own practice. Herein lies my excuse; and though it may not be satisfactory to all, the arguments I have advanced, I think, must be plain to everybody. The sulphates, in substance, are as efficacious as when given in solution; and if so large doses cannot be administered in the former manner, the necessity for such prodigious quantities has never been demonstrated. Let it, therefore, only be admitted, that there is room for suspicion, and perseverance in the old practice is no longer justifiable. The number of horses that exhibit diseased teeth, teaches us to look for some cause. I cannot attribute every case to derangement of the digestive organs, or to idiosyncracy. The latter term rather avoids the question than elucidates it; and the former effect is as likely to be produced by imperfect mastication, consequent upon chemical injury to the teeth, as to be the primary cause of the disease of the masticatory organs.