Some may think that I have chosen a trivial subject, and they will look for frivolous treatment of it. I can only hope that they will be disappointed. There is nothing that the progress of science has taught us more emphatically than this—that we must call nothing insignificant. Seemingly trivial pursuits have led to discoveries which have benefited all mankind, and priceless truths have been dug out of the most unpromising mines. I am not insinuating that anyone's nose is an unpromising mine, but I say that I am persuaded there is wisdom hidden in that organ for him who will observingly distil it out.

It possesses a peculiar and mystical significance not shared by any other feature. This is abundantly proved by common speech, which is one of the most trustworthy of all kinds of evidence. For example, we speak of a person turning up his nose at a good offer. The phrase is absurd, for the power of turning up his nose is one which no human being ever possessed. A shrew can do it, but not a man. Yet the meaning of the saying needs no interpretation. Akin to it is the classical phrase, adunco suspendere naso. What Horace means scarcely requires explanation, but no commentator has successfully explained it. These expressions well illustrate the mystery that enshrouds our most salient feature. They show that, while everybody can see that disdain is expressed through the nose, nobody can define how it is done. Then there is that curious expression "put his nose out of joint," which is quite inexplicable, the nose being destitute of joint. There are many other phrases and also gestures which point in the same direction, but need not be cited, being for the most part vulgar. Allusions to the nose have a tendency to be vulgar, which is another mystery inciting us to investigate it. So let us proceed.

The first thing required by the principles of scientific precedure is a definition. What is a nose? But this proves to be a much more difficult question than anyone would suspect before he tried to answer it. The individual human nose we can recognise, describe or sketch more easily than any other feature, but try to define the thing nose in Nature and it is a most elusive phenomenon. When we speak of a man being led by the nose we imply that it is a part of him which is prominent and situated in front, when we speak of keeping one's nose above water we refer to it as the breathing orifice, but when we say that this or that offends our nose we are regarding it as the seat of the sense of smell. I believe that all these three ideas must be included in any definition. It should follow that insects, which breathe through holes in their sides, cannot have noses, and this is the truth.

Fishes, too, though they may have snouts, have not noses, because they breathe by gills. In truth, it seems that the nose was a very late and high acquisition, almost the finishing touch of the perfected animal form. And incidentally this leads us to notice what a great step was taken in evolution when the breathing holes were brought up to the region of the mouth. For the sense of taste is necessarily situated in the mouth, and the sense of smell is in close alliance with it. The mouth tastes food dissolved in the saliva during the process of mastication, and the primary use of the sense of smell is to detect and analyse beforehand the small particles given off by food and floating in the atmosphere.

A good many years ago, when the late Sally chimpanzee was the darling of the Zoological Gardens in Regent's Park, I watched her eating dates. She was an epicure, and always peeled each date delicately with her preposterous lips before eating it, and during the process she would apply the date to her nose every second to test its quality or enjoy its aroma. The action was indescribably comical, but what would it have been if her nostrils had been situated among her ribs? Imagine a mantis, for example, as he chews up a fly, lifting one of his wings and applying it to his flanks to see if it smells gamey. That is where some naturalists believe that the sense of smell is situated in insects. Others, however, think, with reason, that it is in the antennae or mouth. Nobody knows; the senses of the lower animals seem to be stuck about all parts of the body.

But, even if the sense of smell is at the mouth, how limited must its usefulness be when it can only deal with substances that are held to it! A new era dawned when the passages by which the breath of life unceasingly comes and goes were transferred to the region of the mouth also. The nerves of smell quickly spread themselves over the lining membrane of those passages and became warders of the gate, challenging every waft of air that entered the body and examining what it carried. Thenceforth this region comprising the mouth, nostrils and surrounding parts holds a new and high place in the economy of the body, for the headquarters of the intelligence department are located there, and all the faculties of the brain converge on that point. Of course, the eyes and ears claim a share, but they are not far off.

Now it is being recognised more and more clearly by medical and physiological science that when the mind is much directed to any part of the body it exercises an influence in some way not understood on the flow of blood to that part to a degree which may seriously affect its functions and even its growth. When a person is suffering from any nervous affection, from heart disease, or even from weakness of the eyes, it is of the utmost importance to keep him from knowing it if possible, for if he knows it he will think about it, and that will inevitably aggravate it. This principle is well recognised in systems of physical culture. And surely it is impossible that so much intelligence should pass through that one sensitive region of the body which we are considering without affecting its growth and structure. Every muscle in it becomes quick to respond to various sensations in different ways, till the very recollection of those sensations will excite the same response.