POSTERIOR RHINOSCOPY.--Posterior rhinoscopy is much more difficult than laryngoscopy or anterior rhinoscopy, and requires more patience and dexterity on the part of the examiner than either of the former, because but very few persons have control over the movements of the velum palati, and in most of these the upper portion of the pharyngeal wall is so sensitive that the slightest touch with an instrument gives rise to reflex cough and to gagging. In many cases, however, with patience and skill the naso-pharyngeal cavity and the posterior portion of the nasal cavities can be illuminated and inspected. To do this the patient is placed in the same position as for laryngoscopy, except that the head is not inclined backward, and after the mouth is opened as wide as possible the light from the reflector is thrown into the oral cavity. The tongue is then depressed with a tongue depressor. This instrument in its simplest form in which it is daily used by the practitioner for examining the fauces is the handle of a spoon. For laryngoscopic or rhinoscopic purposes, however, the spoon is not to be recommended, because the hand holding it must be on a level with the mouth, thus obstructing the view and light. An instrument has therefore been constructed which obviates this difficulty. It consists of a leaf-shaped blade of silver or German silver bent at right angles and inserted into a flat wooden handle. The lower surface of the blade is slightly concave, and ribbed so as to take a better hold of the slippery back of the tongue, and from the bend is about 3 inches in length. It is introduced into the mouth as far back as possible, and pressed upon the back of the tongue while the hand of the examiner is below the chin of the patient. For the sake of convenience in carrying the instrument the blade has been so hinged to the handle that it will fold up against the latter and will {38} open at a right angle with it (Fig. 15). A more elegant and lighter instrument of the same description has lately been introduced in which the handle is also made of metal, and, like the blade, is heavily nickel-plated, and which when folded can be carried in a pocket-case. Soon, however, the metal tongue depressor becomes tarnished by the secretions of the mouth or by the substances used for applications to the throat, and then presents an appearance disgusting to many patients, who will not on that account submit to its use. For the sake of greater cleanliness, J. Solis Cohen devised a tongue depressor made of hard rubber, which is known as Cohen's tongue depressor (Fig. 16). It consists of a piece of ebonite bent upon itself, either end being a little over 3 inches long. The bend being more than at right angles, the hand holding the instrument rests underneath the chin of the patient; but if a different curve be desired for any particular case it can easily be obtained by placing the instrument for a little while in hot water. When soft it can be