sions appear to be continually made on the same part of the brain in succession:—with respect to those received by the eye, a new set of objects is almost every moment impressed on the whole organ, and consequently transmitted along the nerves to the same receptacle in the brain[1]. It follows from this last observation (which is not a speculative refinement but a plain matter of fact) that the sphere occupied by different vibrations is constantly the same, or that the same region of the brain belongs equally to a thousand different impressions, and consequently that the mere circumstance of situation is insufficient to account for that complete distinctness, of which our ideas are capable.
From these several considerations taken together I cannot help inferring the fallacy of the Hartleian doctrine of vibrations, which all along goes on the supposition of the most exact distinction and regular arrangement of the places of our ideas, and which therefore cannot be effectually reconciled with any reasoning that excludes all local distinction from having a share in the mechanical operations of the human mind. For if we suppose the succession of our ideas to be carried on by the communication of the impulse belonging to one idea to the contiguous cell, or dormitory of another idea formerly associated with it, and if we at the same time suppose each idea to occupy a separate cell which is inviolable, and which it has entirely to itself,
- ↑ Those of the touch admit of the greatest variety in this respect from the general diffusion of that sense over the whole of the body, and those which depend on hearing from the small part of the ear which is in general distinctly affected by sound at the same time. As to the taste and smell, the stimulants applied to these senses are such as for the most part to act on a large proportion of the organ at once, though only at intervals. The direction of smells is hardly distinguishable like that of sounds.
