Convincing the reader that perfume-making is an art form is easy for these authors: the real joy of this husband and wife's dazzlingly comprehensive compendium is in its case for perfume criticism as the even greater art. With descriptions that are frequently more delicious than their subjects, the writing is the olfactory equivalent of mouthwatering. Read their words on Chanel No 5 and you'll feel as though you've inhaled lungfuls of the stuff. They're also exhaustive, tackling seemingly every perfume under the sun as they intersperse praise with reviews that are as curt as a flick of a fragrant wrist: one scent is dismissed as a "tooth decay", while Cruel Intentions is a "thin, uncertain thing with no discernible intent, cruel or otherwise".

The 20th century so privileged eyes and ears that we seldom notice how much more it offered the nose. Chemical experiments in synthesising perfume materials began in the 19th century, when William Perkin, who had already given the world the ample gift of the first aniline dye (mauvine, sluiced out of coal tar waste), discovered how to change the structure of organic compounds at a molecular level. He introduced salicylaldehyde from carbolic acid to acetic anhydride from vinegar and the Perkin reaction filled the lab not with pickled tar but the scent of new-mown hay. What Perkin first inhaled in 1868 replicated the exhalation of tonka beans, a South American spice - in French, coumarou, so Perkin named his odour coumarin. (It's still in Yves Saint Laurent's gorgeous Kouros.)

The idea, as with dyes, was the repeatable recreation of reality for a farthing. Perfumery ingredients were expensive because they were obscure, low-yield, vulnerable to bad harvests, trade routes, a clammy cellar. Even when a perfumer scraped civet from the glands of an Ethiopian cat or scooped half a drop of attar from a macerated estate of roses, they were unpredictable. But tinker with the new trinitrotoluene (TNT) as Albert Baur did in 1888 in the expectation of making an even bigger bang - and up comes musk baur, smelling like extract of the pods of Himalayan deer and the droppings of rare Algerian gazelles, but at a thousandth of the price, and reliably perfect every time. And, as Luca Turin explains, get a nose composer to arrange each synthesis - vanilla vanillin (1874), bitter leather quinolines (1880), violet ionones (1893), peachy lactones (1906), and the rest of a list that advances incrementally into the present - add a dab of naturals to a lab of benzene, and what happens goes beyond chemistry into post-representational art.

Aimé Guerlain, who collaged Jicky in 1889, or his son Jacques, composer of Mitsouko, 1919, bottled the timbre of a time. As Turin writes, Aimé's 1906 Après L'Ondée (after the rainshower), which he arranged from then-new heliotropin, plus iris, thyme, rosemary and sage, has the "unresolved but effortless feel of the watery piano chords that make Debussy's pieces so poignant". Besides being contemporary with Debussy's Images, Après L'Ondée overlaps in more than era with Monet's first waterlily paintings: they are all meditations on the senses and their mortal limitation. The perfume depends on a radical sensibility, as did Debussy's retreat from full romantic orchestra to a fluid solo piano; and on revolutionary science, as did Monet's use of the latest cobalt and manganese pigments to paint the "true colour of the atmosphere", violet: "fresh air is violet".

Turin's entries in his alphabetical guide to fine fragrances are brilliant exercises in synasthaesia; to him, perfume is a hallucinogenic substance that links everything. Each paragraph awarded to a masterpiece mix covers chemistry, biology, composition (with professional footnote on composer), commercial and political history (the European Union polices ingredients if they put the wearer, maker or environment at risk), personal memories, fantasies, and cross-references to arts, high and low. Consider his analysis of Eau Sauvage, by Edmond Roudnitska for Dior in 1966. He references Garamond type, Prokofiev, Jascha Heifetz and his Guarneri violin, pine needles and rosemary, Vietnamese beef salad, Transformer toys and hedione, aka methyl dihydrojasmonate, discovered in 1962 and capable of moistening florals until they feel fresh as dawn. Such a review could be a dog's dinner, or, worse, all that a dog can sniff the length of a back alley, but it's so exact that it's a kick, a written spritz of cologne. I sprayed on Eau Sauvage again, and for the first time could put a name - that salad - to its lime and coriander.

Now and again I've consulted online perfume blogs, by addicts for addicts, only to give up because of the ineffability that is their common language. Aromas waft; adjectives shouldn't. The dialect of oenophiles (gooseberries, bananas) is grounded in comparison. If there is to be any hope of persuading people to make perfume as much a quotidian reward as wine and food have become these past 30 years, there has to be a way to write about it that excites us, makes us curious, makes us laugh. Turin has found it. I've just blown all my pocket money on sampling an unknown five-star wonder, Guerlain's Habit Rouge, and it's Turin's fault for describing it as "soft and rasping, like stubble on a handsome cheek". (Eau de early Harrison Ford, as it were.) His approach reminds me of the Action Cook Book and Ou est le Garlic?, written and illustrated by Len Deighton in the 1960s and my teen introduction to cuisine. Deighton assumed his readers barely knew where our mouths were and remedied that through gastronomical science essays, comic-strip recipes, and commentaries that shared Turin's multicultural references - fast cars, old planes and actresses who had slept with François Truffaut. A lifetime later I still quote Deighton on the physics of overfrying eggs, and I shall be reciting Turin into old age on Le Feu d'Issey: perfume as a "portable form of intelligence . . . fresh baguette, lime peel, clean wet linen, shower soap, hot stone, salty skin . . . fly past one's nose at warp speed".

There is a second voice in this book, that of Tania Sanchez. Both authors point out that fragrances aren't aphrodisiacs or sex pheromones, and sulk at the narrow definitions of sexual identity standard in the fragrance trade, but their contributions are terrifically gendered, and that's a compliment. She provides the advice for novices and the true confession that starts with the "belief that Old Spice/Brut/English Leather is the natural odour that God caused fathers to emit after shaving" and ends with enlightenment, Chanel's Bois des Iles, equivalent to a little black cashmere dress, which she wore whenever she "needed extra insulation from the cold world".

For a while I thought she was playing Eva Marie Saint to Turin's Cary Grant, but her voice is faster and wackier than that, more the young Barbara Stanwyck, and there's screwball comedy in their interaction. They disagree about classics; he quotes her approvingly (that salad interpretation is hers), she quotes him disbelievingly; they spar through hundreds of one-word or two-line dismissals of inept pongs - "burial wreath", "grim floral", "canned fruit".

Nobody is meant to begin this volume at the dedication, as I did, and keep on going to the glossary, but should you do so, you'll have witnessed a witty courtship conducted through competitive discernment: when I learned they were married, I wasn't a bit surprised. Not after Sanchez's wicked whistle at a slug of Stetson, which is promoted as quintessence of manly Montana but is "as rugged and masculine as the lingerie level at Saks Fifth Avenue . . . I'd truly love a man who wore this, but in the absence of one, I'll gladly wear it myself."

Romance with brains needs adversity to flourish, and to create this guide Turin and Sanchez gallantly went through odorous hell. About 40% of concoctions were classified awful or disappointing and another 40% only adequate. High prices, movie star ads, prestigious houses, gifted creators, sculptural flacons, historic longevity, massive sales: none guarantees that the liquid won't smell of mall rat effluvia, sports sneaker juice ("bloodless, gray, whippet-like, shivering little things"), Paris Hilton's Just Me ("barf-bag floral") or absolutely nothing with a faint hint of melon in the case of L'Eau d'Issey. Sanchez claims everybody knows at least five people who wear this: we may not move in the same circles. Contrariwise, cheapness is no deterrent to sublimity, since 150 years of research have rearranged enough molecules to supply superb macrocyclic musks to manufacturers of laundry detergent. All the way through this book I was saddened, as I am when I see a beautifully designed plastic milk bottle, that we don't respect the scents, dyes and objects created from carbons bequeathed by long-set suns, just because they've been dirt cheap for 40 years.

Turin and Sanchez are not conventional snobs. Besides the Guerlain family, who have been getting it mostly right since Jicky, the most laudatory entries are for Estée Lauder, "faithful keeper of one of the most consistently high-quality lines of fragrances ever created". I'd never thought of sniffing her commissioned brews until I wrote her obituary and wanted to understand why Youth Dew, which she spilt on the carpet at the Galeries Lafayette as an olfactory calling card, had made her fortune. I bought samples of Lauder greats, which turned out to be Paris as imagined by the art department at MGM, a distillation of yearning more potent than the real thing.

The least expensive preparation in this book rates its most tender, five-star review: Caldey Island Lavender, by Hugo Collumbien, now in his 90s, for the South Wales monastery. Turin says its gently handled linalool, lavender's 10-carbon alcohol, results in "endlessly blue daylight air": it reminds me of Vermeer's use of the precious pigment ultramarine, made from lapis lazuli and traditionally reserved for the Virgin Mary's robe, on the apron of a servant pouring milk. A blessing for the daily round and common task, anyway: £7.75 a bottle.