The most distinctive symptoms of this form of _nasal gleet_ are obtained by percussing the sinuses, and in those cases in particular in which the accumulation is confined to one side of the head, the contrast between the two sides is unmistakable. By gently tapping the forehead with the middle finger from one eye to the other the flat solid sound on the diseased side is easily distinguished from the clear drum-like resonance on the healthy one. By tapping on the bone beneath each eye and just above the ridge on the side of the upper jaw, the difference between the two sides will be recognized in the same way. In some old standing cases increased tenderness and slight bulging of the bones over the affected sinuses are often superadded to the other symptoms. The eye on the affected side is usually retracted so as to seem smaller. _Treatment._ In some cases the use of tonics and astringent injections as recommended for the treatment of _ozœna_ will prove successful, but more usually it is needful to open and inject the sinuses. For this the following articles are required: scissors, a knife, forceps, a trephine or circular saw from half to three-fourths of an inch in diameter and a whalebone or metallic prob. The horse is thrown and made fast with the diseased side of the head uppermost. A point is then selected on a line drawn between the centres of the two eyeballs and an inch to one side the median line of the forehead; the hair is closely removed with the scissors, and a semi-circular flap of skin over an inch in diameter is dissected from the bone and turned back toward the poll. The trephine is next applied on the bone and a circular portion, having been cut through, is pulled out by the forceps, when the imprisoned pus will commonly ooze from the opening. A second point is chosen just above the lower end of the bony ridge of the upper jaw already referred to and opposite the third molar tooth, counting from before; the hair is removed as before, a flap of the skin raised upward and backward and the bone trephined to open the second sinuse. The point of election for this orifice is more important than that of the first. If it is too near the eye the lower part of the sinus, which is separated from the upper by an imperforate bony plate, is not opened and may continue to keep up the discharge from the nose. If on the contrary it is made too low down, the lower sinuse only is opened and the upper being imperfectly washed out from the wound in the forehead will keep up the discharge. Either then this plate must be struck with the trephine or it must be afterward perforated to secure a favorable result. The prob introduced by the wound in the forehead should further appear at the lower orifice.