THE SENSE OF SMELL. 173 



a provision wisely and kindly made, in order to guide them to their pro- 

 per food, or to fit them for our service. It may possibly be the medium 

 through which much evil is communicated. Certain particles of a delete- 

 rious nature may be, and doubtless are, arrested by the mucous membrane 

 of the nose, and there absorbed, and the constitution, to a considerable 

 degree, becomes affected. Hence appears the necessity for attention to 

 ventilation, and especially to prevent the membrane of the nose from 

 being habitually stimulated and debilitated by the effluvia generated in a 

 close and hot kennel. 



M. Majendie instituted some curious experiments on the sense of smell- 

 ing, and he was led to believe that it depended more on the fifth pair of 

 nerves than on the olfactory nerve. He divided the fifth pair, and from 

 that moment no odour, no puncture, produced the slightest apparent im- 

 pression on the membrane of the nose. In another dog he destroyed the 

 two olfactory nerves, and placed some strong odours beneath the nostrils 

 of the animal. The dog conducted himself as he would have done in his 

 ordinary state. Hence he concluded it probable that the olfactory nerve 

 was not that of smelling. 



The simple fact, however, is, that there are two species of nerves here 

 concerned those of common and of peculiar sensation. The olfactory 

 nerve is the nerve of smelling, the fifth pair is that of common sensation. 

 They are to a certain degree necessary to each other. 



Scent. This leads us to the consideration of the term " scent." It 

 expresses the odour or effluvium which is constantly issuing from every 

 animal, and especially when that animal is in more than usual exercise. 

 In a state of heat or excitement, the pores of the skin appear relaxed, and 

 a fluid or aqueous vapour is secreted, which escapes in small or large 

 quantities, adheres to the persons or substances on which it falls, and is, 

 particularly, received on the olfactory organs. The hound, at almost the 

 earliest period, begins to comprehend the work which he has to perform. 

 The peculiar scent which his nostrils imbibe urges him eagerly to pursue ; 

 but the moment he ceases to be conscious of the presence of the effluvium, 

 he is at a perfect loss. 



Mr. Daniel, in his work on the Chace, very properly observes, that 

 " the scent most favourable to the hound is when the effluvium, constantly 

 perspired from the game as it runs, is kept by the gravity of the air at 

 the height of his breast. It is then neither above his reach nor does he 

 need to stoop for it. This is what is meant when the scent is said to be 

 breast-high." 



When the leaves begin to fall, the scent does not lie well in the cover. 

 It frequently alters materially in the same day. This depends principally 

 on the condition of the ground and the temperature of the air, which 

 should be moist but not wet. When the ground is hard and the air dry, 

 there will seldom be much scent. The scent rarely lies with a north or 

 east wind. A southerly wind without rain is the best. Sudden storms 

 are sure to destroy the scent. A fine sunshiny day is not good ; but a 

 warm day without sun is always a good one. If, as the morning advances, 

 the drops begin to hang on the bushes, the scent will not lie. During a 

 white frost the scent lies high, and also when the frost is quite gone ; 

 but at the time of its going off the scent never lies. In a hard rain, if 

 the air is mild, the scent will sometimes be very good. A wet night 

 often produces the best chaces. In heathy countries, where the game 



