A text-book on diseases of the ear, nose and throat . tient the annoyance of the heat of the gas-flame. Six-volt lights arethe most practical, and the cylinder containing the light and its con-densing lens should never exceed five-eighths of an inch in reason for this is that the rays leaving a wide cjdinder form anangle with those returning to the eye from the illuminated object, sothat it is impossible to see to any depth, while the axis of a narrowcylinder can be placed so close to the axis of the eye that the angleformed by the projected and returning ray is of no consequence,
A text-book on diseases of the ear, nose and throat . tient the annoyance of the heat of the gas-flame. Six-volt lights arethe most practical, and the cylinder containing the light and its con-densing lens should never exceed five-eighths of an inch in reason for this is that the rays leaving a wide cjdinder form anangle with those returning to the eye from the illuminated object, sothat it is impossible to see to any depth, while the axis of a narrowcylinder can be placed so close to the axis of the eye that the angleformed by the projected and returning ray is of no consequence, as therays are for all practical purposes parallel. Most of the cylinders fur-nished by mechanics are too wide, their idea being to give a large illu-minated field by means of a large lens, while all that is needed is a spotof light one and one-half inches in diameter. Of all the many styles of nasal specula in use the most satisfactoryis the simple bivalve form. The one shown in Fig. 99 has proved mostserviceable for examinations and THE examinatio:n^ of the nose and nasopharynx. 245 The first step in rhinoscopy is the inspection of the vestibule of thenose without a speculum, as there are often found eczematous crusting,patches, and fissures in this region which render examination with aspeculum inadmissible by reason of its painfulness. Little children feara speculum, and, as their vibrissas are undeveloped, it is usually easy toinspect infantile nasal passages without an instrument. The nasal specu-lum is to be opened gently, as its rough use causes a good deal of x) examiners head should be so placed that his eyes are on a levelwith the inferior meatus. The foreshortening in the appearance of theparts makes the aspect of the nasal interior rather confusing to thoseunused to seeing it, as everything is viewed ai)parently on edge. It iswell to follow a systematic course in making a nasal examination, other-wise it is easy to overlook something in inspe
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