Step 2. Pass along the interior of the catheter a yard of twine, and draw its end through the eye of the catheter a few inches, then introduce the catheter through the naris directly backwards, not upwards nor downwards, because, when the patient is upright, the floor of the nose is nearly horizontal. When the catheter has reached the pharynx, the finger, or a forceps, must be passed through the mouth to catch the string hanging from the end of the catheter and bring it out of the mouth, where it is held while the instrument is withdrawn from the nose. The step is repeated in the other nostril if required. Step 3. Next wash out the nostrils with a few syringefuls of ice-cold water, in which some tannin is suspended. Step 4. Fasten the double string of the plug to the end of twine hanging out of the mouth (see fig. 72), and then draw out the other end through the nose; this will carry the plug to the pharynx, where the finger guides it over the soft palate and thrusts one of its ends into the naris, where the strings draw it tight. The plug for the anterior nostril is then put in place, and the strings tied tightly over it (see fig. 73). Thus the plug in front keeps the plug behind in place and _vice versâ_. The end of string from the posterior nares, left hanging out of the mouth, must next be tied to the string of the anterior plug to keep it out of the patient’s way, till wanted to withdraw the posterior plug, when that is to be removed. If blood run from both sides, the other nares are stopped by a repetition of this operation. [Illustration: Fig. 72.—Plugging the nares. Belloc’s sound passed through the nares, and projecting at the mouth.] This apparatus is very painful, and, if borne so long as a couple of days, should always be taken out then. If bleeding recur, which is very unlikely, fresh plugs must be introduced. Sometimes the posterior plugs are soaked in styptic solutions; this is bad, because the bleeding part is not at the posterior nares, and the styptics increase the soreness the plugs themselves produce. [Illustration: Fig. 73.—Plugging the nares; the strings from the posterior plug tied over the anterior plug.] [Illustration: Fig. 74.—Belloc’s Sound, for drawing a thread from the mouth along the nares.] =Belloc’s Sound.=—Fig. 74 is a curved silver cannula like a female catheter, furnished with a long spring stylet, that arches round in a circle when thrust out of the cannula, and has a hole at the end to carry a thread. The long stylet can be unscrewed into two parts, when not in use. The figure represents the instrument with the stylet ready for protrusion, and the same arching forwards after it is protruded.