M. Majendie instituted some curious experiments on the sense of smelling, 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 impression 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 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. Daniel, 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."