Fatigue and then exhaustion of a sense-organ, rendering it finally irresponsive to a particular stimulus, is, of course, familiar to us also in the case of vision, as the soap advertisement of our boyhood with its complementary colours taught us. Taste manifests the same phenomenon, for which reason (so he says) the cheese-taster in Scotland swallows a little whisky after each of the different samples he tries. But, curiously enough, the healthy ear is not thus dulled save by a very loud, persistent noise, and then there is the risk of permanent damage to the hearing organ. Some forms of tactile sensation, also, would seem to remain ever sensitive, for, although it may be possible to become so inured to pain as to ignore it, yet that is probably a mental act, and it is said, moreover, that men have been tortured to death by the tickling of the soles of their feet. But, as we have already seen, of all the senses none so quickly becomes inert under stimulation as olfaction. Why it would be hard to say, unless, like the exhaustion of colour-vision, it is due to the using up of some chemical reagent in the sense-organ. At all events, if you wish to appreciate the full intensity of a smell, you should arrange to come upon it from the open air. I wonder if this, or something like it, is the reason why England was the first country in the world to wage war against its stenches. For the English are of all races the most addicted to fresh air. Consequently, they are the most likely to keep habitually their olfactory sense unspoiled and virgin. This, I admit, is only pushing the matter a step further back, and we are still left with the question: Why is it that the English are so fond of the open? Largely, I imagine, because their climate is so damp that an indoor atmosphere is always a little oppressive to them. Whatever may be the reason, however, there is no doubt that the keen, clean chill of an English April day, especially when the wind is in the east (_pace_ Mr. Jarndyce), brings to us an exaltation of spirit that surpasses the exhilaration of wine, and at the same time renders us impatient with mustiness and fustiness, intolerant of domestic stuffiness, and frankly disgusted with the pungent, prickly vapours of intimate humanity in the mass. The wind on the hilltop is our aspiration, our ideal. Hence, maybe, the Public Health Acts, and also the national tub.