146 THE PHYSIOLOGY OF THE SPECIAL SENSES. 



animals, because it is not so much required, in our present condi- 

 tion, for hunting out our prey or scenting danger at a distance. 

 But the sense is occasionally very highly developed in individuals, 

 and this, or something allied, may be the case in the persons who 

 are reputed to be able to state where water will be found on boring, 

 without any previous knowledge of the locality. 



That any persons should be thus endowed by Providence with 

 such a special power apart from the rest of mankind, for the sole 

 purpose of making a livelihood, may be sufficient explanation for 

 the uneducated ; but if the power be there, it seems possible that 

 it is the epithelium of their organ of smell which is capable of 

 appreciating some atmospheric condition insufficient to affect most 

 of us. At least, this is a possible explanation. 



The sense of taste, so-called, is very largely the sense of smell, 

 and not taste at all. Thus, the ordinary aromatic flavouring sub- 

 stances used in cookery do not affect the tongue and palate, but 

 the smell organ in the nose. In fact, the only things we really 

 taste are bitter, sweet, and acid substances. The senses of taste 

 and smell are. when both put together, very small in the informa- 

 tion they give us of our surroundings, A smell gives us no idea 

 of the shape, size, or quality of a substance ; nor is it of any use 

 except to warn us of dangerous materials in the atmosphere or 

 food, or to stimulate our desire for food. 



Of the other senses, time compels me to leave out very much 

 that might be said of extreme interest to us all, and I must content 

 myself, in conclusion, with a few words as to the sense of Pain. 

 Why do we suffer pain ? What good is it ? What is it ? These 

 questions must occur very frequently to all who are themselves 

 sufferers, or have the said opportunities of seeing pain in others. 



To take the last question first, pain is a conscious impression 

 of excessive or harmful peripheral stimulation. It is to a certain 

 extent possible to localise it, but we get little or no information as 

 to the cause of the pain. The w^hole sensation begins and ends 

 in the consciousness of ])ain and the attempt to get rid of it. Pain 

 varies in many ways, according to the seat of the irritant. Thus, 

 certain noises, such as the squeak of a slate pencil, produce on 

 certain persons not only the sense of sound, but also of actual 

 pain. So also with vision, though the pain differs from that pro- 



