226 



THE SPECIAL SENSES. 



fluid; easily escapes. If a live insect has gained entrance 

 to the ear, it may first be suffocated by pouring a little oil 

 upon it, and afterward removed by syringing the ear as 

 just mentioned. 



108. The^rp&oval of ear-wax is generally unnecessary; 

 for, as we havVbefore seen, Nature provides that the excess 

 of it shall become dry, and then spontaneously fall out in 

 the form of fine scales. The danger from the introduction 

 of solid implements into the outer ear is chiefly found in 

 the fact that the membrane which lies at the bottom of it 

 is very fragile, and that any injury of it is liable to be per- 

 manent, and to permanently impair the hearing of the 

 injured ear. 



QUESTIONS FOR TOPICAL REVIEW. 



Give a* full statements as yon can on the following subjects : 



1. Production of sensation 177, 178 



2. Variety of sensations 178, 179 



3. General sensibility 179, 180 



4. The sensation of pain 180 



5. The uses of pain 180, 1S1, 182 



6. Special sensation 182, 183 



7. Orirans of touch 183. 1. W 4 



8. The sense of touch 184, 185, 186 



9. The delicacy of tonch 186. 1S7 



10. Sensations of temperature and 



weight 187, 188 



11. The orsran of taste 188, 1!^ 



12. The sense of taste 189, 191 



13. Relations of taste, etc 190, 191 



14. Influence of education, etc.. 191. 19) 



15. The sense of smell 192, 193 



16. The nerve of smell 193, 194 



17. Uses of the sense of smell. .194, 195 

 IS. The sense of sight 196, 197 



19. Lisrht. and the optic nerve. .197, 198 



20. The organ of sight 19S, 199 



21. The orbits 199 



22. The eyelids 200, 201 



23. The lachrymal fluid 201. 202. 203 



24. The eyeball 2(3. 204 



25. The iiis 2(>5. 206 



26. The retina 206, 207, 2( 8. 209 



27. The crystalline lens 209, 210 



28. Uses of the lens 210,211. 212 



29 Lon? and short sight 212, 213 



30. Function of accommodatioii.213, 214 



31. Old sight, or presbyopia 215 



32. Hearing and sound'. ... .215. 216, 217 

 83. The external ear 217. 218. 219 



34. The middle ear 219222 



35. The internal ear 222. 223, "224 



36. Protection of the sense of hear- 



ing 224, 225, 226 



