91av

FIRST up, I must fly the flag of my olfactory epithelium from the masthead of self-interest. Ever since a virus robbed me of my sense of smell – now thankfully restored – I’ve had a personal fascination for anything smelly, whether it be pleasant, pungent or putrid.

So notwithstanding the fact that you are reading a review by a certified enthusiast, Avery Gilbert’s whistle-stop journey – what the newspapers would call a romp – through, around and inside the nose is remarkably entertaining, and a great read for anyone seeking a tour that awakens the senses.

Everybody who is anybody in the world of scent, and a few impostors too, make an appearance as we bounce from chapter to chapter, learning diverse olfactory gems. For example, mothers prefer the smell of their own baby’s poo to that of others (even in random, double-blind studies), and in 1935 neurosurgeon Charles A. Elsberg was the first person to establish the yardstick for the standard “sniff” (9 cubic centimetres of odorous air, in case you wondered).

To be honest, the nose “knows” very little. Of all our senses, olfaction is the least understood. The discovery of the physiology behind the sense of smell won Linda Buck and Richard Axel a as late as 2004. Yet What the Nose Knows is less interested in the science than in the fun behind the science, which is why Buck and Axel merit barely a mention. The same cannot be said for Omer van den Bergh, who makes people vomit while simultaneously presenting them with a particular unpleasant odour in order to prove that exposing them to that same odour later will make them puke again.

None of this is to suggest that the book is fluffy, but it is certainly aimed at a particular audience, so anybody searching for a point-by-point account of our medical relationship with olfaction should look elsewhere.

Whatever the angle of your interest, though, it is hard to resist the sheer pleasure of reading the factoids packed into this book. Did you know that dimethyl sulphate, a key odorant in oysters, also shows up in tomato paste and pinto-bean farts? And there’s some serious stuff too: in the recent evolutionary past, humans developed subfamilies of odour receptors that our closest relatives, the chimpanzees, do not possess. This is almost certainly because we have only recently learnt to cook and flavour our own food.

Lastly, there’s ephemeral subjectivity. Gilbert proposes his own adjunct to psychologist Donald E. Brown’s list of cultural universals, which already include music, incest-avoidance and death rituals. He suggests adding “every culture has a foul-smelling food” to the list. And while this includes the Icelandic love of rotting shark, and Japanese natto – which tastes like creosote – not much can top P. J. O’Rourke’s description of the effects of eating Korean kimchi: “…a miasma of eyeglass-fogging kimchi breath, throat-searing kimchi burps, and terrible, pants-splitting kimchi farts”. (As you can see, farts figure prominently.)

Of course, the other side of the text’s freely subjective coin means it is open to dispute. Carl Sagan is quoted as saying that “it is clear smell plays a very minor role in our everyday lives”. A very clever bloke, Sagan, but a man who had obviously never suffered the agony of anosmia. You’ll find out what that means in the book, too.