13. =Temporal and facial arteries.=--The pulsation of the trunk of the temporal artery can be felt, between the root of the zygoma and the ear. This should be well known to and used by chloroformists. It is also a convenient pulse to feel in a sleeping patient. The facial artery can be distinctly felt as it passes over the body of the jaw at the anterior edge of the masseter; again near the corner of the mouth close to the mucous membrane: and, lastly, by the side of the ala nasi, up to the inner side of the tendo oculi. By holding the lips between the finger and thumb the coronary arteries are felt under the mucous membrane. The facial vein does not accompany the tortuous artery, but runs a straight course from the inner angle of the eye to the front border of the masseter, just behind the artery. 14. =Eyelids and eyes.=--The opening between the eyelids varies in size in different persons; hence more of the eyeball is seen in some than in others, and the eye appears larger. Although human eyes do vary a little in size, yet the actual difference is by no means so great as is generally supposed. The size of the fissure has much to do with the apparent size of the eye. Contrast the narrow fissure of the Chinese and Mongolian races, and the apparent smallness of their eyes with those of Europeans. As a rule the external angle of the lid is higher than the internal. When not exaggerated, it gives the face an arch and pleasing expression. Evert the lids to see the Meibomian glands; observe their perpendicular arrangement, in the substance of the tarsal cartilages. The free borders of the lids are not bevelled, as described by J. L. Petit and most anatomists, ‘so as to form with the globe of the closed eye a triangular canal for the flow of the tears.’ On the contrary, it is easily seen that the lid margins, when closed, come into accurate contact. Their plane is not exactly horizontal, but slightly inclined upwards. Every time the eye is shut, the ball turns upwards and inwards, so that the cornea is completely covered by the upper lid. This may be well seen by raising the lid of a sleeping infant; also in cases of low fever when the lid is not completely closed. This up-turning of the eye obviously clears the cornea, and protects it from the light. A careful examination of the motion of the lower lid in the act of shutting the eye proves that it is a double motion. The lid is not only slightly raised, but drawn inwards about ¹⁄₁₂ of an inch. This second movement sweeps any particles of dust as well as moisture towards the inner canthus.