In patients _who have not received morphine before narcosis_ the pupil is, as a rule, a guide of some importance. If the pupil is narrow, examination of its reaction to light is generally superfluous. A wide pupil, however, often means one or the other extreme of narcosis. A wide pupil which reacts promptly to light indicates superficial anesthesia; the patient may need more of the anesthetic. A wide pupil which reacts to light sluggishly or not at all means that the danger line has been overstepped; the anesthesia is too deep; the patient must have air. Without knowledge of the reaction, every markedly dilated pupil should be looked upon as prognostic of danger. [Sidenote: Cornea] To touch the cornea repeatedly with the finger for the purpose of obtaining the corneal reflex, is a bad habit. The reflex can be tested just as satisfactorily by shifting the eyelid gently across its surface. A point worth remembering is that in the morphine-anaesthol (or morphine-chloroform) anesthesia the corneal reflex may remain quite active, while with ether it soon becomes feeble or extinct. [Sidenote: Eyelid] A useful indicator of the degree of muscular relaxation is, I believe, the tonicity of the eyelid. The usual arm test is very misleading. Flexing the elbow once or twice may give the impression that the muscles are thoroughly relaxed, and yet, on repeating the manipulation five or six times one may be surprised to obtain a sudden, powerful contraction of the biceps, showing that the patient is still not fully under the influence of the narcotic. Normally the upper lid has a certain tonicity. If it is lifted gently by means of the superimposed ball of the finger it springs back to its natural position promptly. When the patient is fully under the influence of the anesthetic, this tonicity is partly or completely lost and the lid returns sluggishly to its natural position, or not at all. The patient can sometimes be kept in a proper surgical plane by giving a few drops of the anesthetic each time as the tonicity returns, and ceasing when relaxation of the eyelid is obtained. [Sidenote: Secretions] [Sidenote: Individual Idiosyncrasy] When the patient is under anesthesia to the surgical degree the activity of the salivary, sweat and tear glands ceases. The accumulation of mucus in the mouth, the appearance of a tear in the eye, beads of perspiration on the brow all mean that the anesthesia is becoming superficial, that more anesthetic is required. It is worth bearing in mind that these indicators of the depth of narcosis do not, in all individuals, react in exactly the same way. While initiating the narcosis the anesthetist can get his bearings in regard to this point, and watch for any individual idiosyncrasy which may exist. It is unsafe to concentrate the attention on one sign, lest the general aspect of the patient be overlooked.