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.
. — 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 persona 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.
, in his work on the
Chase
, 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 chases. In heathy countries, where the game brushes the grass or the boughs as it goes along, the scent seldom fails. It lies best on the richest soils; but the countries that are favourable to horses are not always so to hounds. The morning usually affords the best scent, and the game is then least able to escape. The want of rest, added perhaps to a full belly, gives the hounds a decided superiority over an early-found fox; and the condition of the ground and the temperature of the air are circumstances of much importance.