On the 7th day of June, 1853, a Stallion was brought under my observation, owned by Christian Kerr, of Centre township, then Union county, which had ten distinct ulcers on his penis, varying in size from a pea to a dime. These ulcers were accompanied with a discharge, sometimes bloody, emitting a very disagreeable odor, that was perceptible at a distance of three or four rods. The attendant of this horse, noticed these ulcers about five days previous to the time I was consulted, when the marks were very small. He remarked to me, that “people declined to allow his horse to cover their mares, stating, that he was diseased with the pox.” And I actually found this to be the case. I dressed the horse, and sent him away. That night I examined all the works veterinary Science that I could command, and found but a single one that made the least mention of the disease, but giving neither the cause or treatment of it. In less than a week, I had over twenty mares to attend, that were affected by the horse. I treated the horse and mares according to the best of my judgment, having first obtained the advice of an eminent human Physician, and I soon became perfect master of the disease, and saved all but two mares that were placed under my care. I found, that where the disease had taken deep root and entered the system, every effort to save the animal was in vain, and hence, I am satisfied, that where the disease has been suffered to go unchecked, until it became so deeply rooted as to vitiate the whole system, it is incurable. CAUSE. Mares will sometime get in season early in the spring, when they will discharge a thin, whitish fluid, resembling bluish milk, of a glutinous nature, but very clean. If the mare does not become pregnant until the latter part of May or the beginning of June, this fluid will change into a mattery state, and will affect the parts in the region of the womb to such an extent as to cause rawness and inflammation. A mare, that is in a condition as described above, is very apt to communicate to the horse covering her, the disease of Gonorrhœa, or Clap, especially if such horse be permitted to cover from five, twelve and fifteen mares a day, where another horse, covering only once every few days will escape unharmed. The reason of this is evident; the penis of the one covering so many mares, becomes very tender and almost transparent, so as almost to cause the blood to shine through it. Another instance in which a horse is apt to become diseased, is, when he is suffered to cover a mare on the ninth day after she has undergone the process of foaling. At this period there is still a discharge of bloody matter, which is very apt to generate clap in an animal of the opposite sex. DESCRIPTION OF DISEASE.