942. Sometimes the substance is concealed under the upper eyelid, and it may then be exposed by turning back the lid in the following manner: Take a knitting-needle, or small, slender piece of stick, which is perfectly smooth, and place it over the upper lid, in contact with, and just under the edge of the orbit; then, holding it firmly, seize the eyelashes with the fingers of the disengaged hand, and gently turn the lid back over the stick or needle. The inner side of the lid can then be examined, and any substance removed that may have been there concealed. Too many trials ought not to be made, if unsuccessful, as much inflammation may be induced; but a surgeon should be consulted as soon as possible. _Observation._ Eyestones ought never to be placed in the eye, as they often cause more pain and irritation than the evil which they are intended to remedy. -=-=-=-=-=-=-=-=-=-=-=-= 942. How removed from the upper eyelid? Why should not eyestones be used? -=-=-=-=-=-=-=-=-=-=-=-= CHAPTER XLVI. THE SENSE OF HEARING. 943. The sense of hearing is next in importance to that of vision. Through this sense we are enabled to perceive sounds, that not only subserve to our comfort and pleasure, but are instrumental in promoting our intellectual enjoyments. The organ of hearing, or the ear, is one of the most complicated in the human body. ANATOMY OF THE ORGANS OF HEARING. 944. The EAR is composed of three parts: 1st. The _External Ear._ 2d. The _Tym´pan-um_, or middle ear. 3d. The _La´by-rinth_, or internal ear. 945. The EXTERNAL EAR is composed of two parts: The _Pin´na_, (pavilion of the ear,) and the _Me-a´tus Aud-it-o´ri-us Ex-ter´nus_, (auditory canal.) 946. The PINNA is a cartilaginous plate which surrounds the entrance of the auditory canal. It presents many ridges and furrows, arising from the folds of the cartilage that form it. _Observation._ The pinna, in many animals, is movable; in those that pursue their prey, it is generally directed forward; in timid animals, as the hare and rabbit, it is directed backward. In man, this part is but slightly under the control of the will. -=-=-=-=-=-=-=-=-=-=-=-= 943. What is said of the importance of hearing? Is the ear complicated in its structure? 944-962. _Give the anatomy of the organs of hearing._ 944. Of how many parts is the ear composed? Name them. 945. Give the parts of the external ear. 946. Describe the pinna. What is said in reference to the pinna of many animals? -=-=-=-=-=-=-=-=-=-=-=-=