I begin, then, with the consideration of that very simple order of our sensations which we ascribe to our organ of
SMELL.
The organ of smell, as you well know, is principally in the nostrils,—and partly also in some continuous cavities on which a portion of the olfactory nerves is diffused.
Naribus interea consedit odora hominum vis
Docta leves captare auras, Panchaia quales
Vere novo exhalat, Floræve quod oscula fragrant
Roscida, cum Zephyri furtim sub vesperis hora
Respondet votis, mollemque aspirat amorem.[74]
When the particles of odour affect our nerves of smell, a certain state of mind is produced, varying with the nature of the odoriferous body. The mere existence of this state, is all the information which we could originally have received from it, if it had been excited previously to our sensations of a different class. But, with our present knowledge, it seems immediately to communicate to us much more important information. We are not merely sensible of the particular feeling, but we refer it, in the instant,—almost in the same manner, as if the reference itself were involved in the sensation,—to a rose, hemlock, honeysuckle, or any other substance, agreeable or disagreeable; the immediate presence, or vicinity of which we have formerly found to be attended with this particular sensation. The power of making the reference, however, is unquestionably derived from a source different from that, from which the mere sensation is immediately derived. We must previously have seen, or handled, the rose, the hemlock, the honeysuckle; or if, without making this particular reference, we merely consider our sensation of smell as caused by some unknown object external to our mind, we must at least have previously seen or handled some other bodies, which excited, at the same time, sensations analogous to the present. If we had been endowed with the sense of smell, and with no other sense whatever, the sensations of this class would have been simple feelings of pleasure or pain, which we should as little have ascribed to an external cause, as any of our spontaneous feelings of joy or sorrow, that are equally lasting or equally transient. Even at present, after the connexion of our sensations of a fragrance with the bodies which we term fragrant, has been, in a great measure, fixed in our mind, by innumerable reflections, we still, if we attend to the process of the reference itself, are conscious of a suggestion of remembrance, and can separate the sensation, as a mere feeling of the mind, from the knowledge of the object or external cause of the sensation, which seems to us a subsequent state of the mind, however close the succession may be. Indeed, what is there which we can discover, in the mere sensation of fragrance, that is itself significant of solidity, extension, or what ever we may regard as essential to the existence of things without? As a mere change in the form of our being, it may suggest to us the necessity of some cause or antecedent of the change. But it is far from implying the necessity of a corporeal cause;—any more than such a direct corporeal cause is implied in any other modification of our being, intellectual or moral,—in our belief, for example, of the most abstract truth, at which we may have arrived by a slow developement of proposition after proposition, in a process of internal reflective analysis,—or in the most refined and sublime of our emotions, when, without thinking of any one of the objects around, we have been meditating on the Divinity who formed them—himself the purest of spiritual existences. Our belief of a system of external things, then, does not, as far as we can judge from the nature of the feelings, arise from our sensations of smell, more than from any of our internal pleasures or pains; but we class our sensations of smell as sensations, because we have previously believed in a system of external things, and have found, by uniform experience, that the introduction of some new external body, either felt or seen by us, was the antecedent, of those states of mind which we denominate sensations of smell, and not of those internal pains or pleasures, which we therefore distinguish from them, as the spontaneous affections of our own independent mind.