It is less easy to define smell and the odorous object, than the subjects which have just been treated of, as the nature of odour is not so clear to us as is that of either sound or colour; and the reason of this is, that our sense of smell is inaccurate, is less delicate, in fact, than it is in many animals. Thus, man has but a coarse smell, and is never sensible of any thing odorous without associating therewith an impression of something painful or grateful; and this seems to indicate an organ imperfectly constituted. It is probable that colours are perceived by creatures which have hard eyes in this same manner, and that shades of colour invariably make upon them an impression of something to be afraid of or otherwise. The human race is circumstanced in a like manner with respect to odours; and there seems to be an analogy between taste and kinds of savours, and smell and kinds of odours, but as taste is a kind of touch, and touch of all man's senses the most perfect, his taste is more delicate than his smell. With respect to other senses, man is far behind many animals, but he is especially
