Textile experts believe Jeremy Bentham's underwear to be the oldest in England
It is humanity as Plasticine. The truncated figures twist in the centre of the canvas. In many cases, they are all but unrecognisable, deliquescing into fleshy blobs. Their heads are smeared, squashed, mangled. Yet the overall effect is undeniably impressive. Who else but the incomparable Francis Bacon? His work has never looked better than in the Hayward exhibition devoted to studies of the human body. Dodging round the bossy film crews on the press day, I found myself intrigued by the curious variety of props that Bacon chose to include with his subjects. He was particularly drawn to umbrellas and toilet bowls (Bacon painted the plumbing with fastidious care, including U-bends and pipe joints). In one work, a drastically scalped figure wears a pair of cricket pads.

But the most frequently recurring motif is metal tubing, formed either into rectangular boxes or huge circulate hoops. It seems to me that these mysterious devices stem from Bacon's brief spell as a furniture designer in the late Twenties. A surprising photograph in David Sylvester's book Interviews with Francis Bacon reveals that this dark master of distortion produced rather desirable pieces in the art deco style: stainless-steel stools with cow-hide seats, circular glass tables on metal stands, and vast oval mirrors. Although Bacon later denigrated them, the same shapes crop up over and over in his paintings.

If you happen to find yourself consumed with desire for one of the works in the Hayward, don't despair even though you lack the requisite zillions. It is easy to produce your own Bacon - or at least a large section of one. A study of his technique by Andrew Durham in 1985 revealed that for the background of many of his works, "he used emulsion house paints which are fast-drying and convenient for the large expanses of flat colour which provide the setting for the image". A trip to my local Homebase offered an interesting insight into the artist's palette.

For example, around three-quarters of Triptych - Studies of the Human Body (1970) - which would probably sell for upwards of pounds 3 million if it came on the market - appears to be a lavender shade of Crown Solo One Coat called "Sweet William", retailing at pounds 14.99 for a 2.5 litre tin. Similarly, the garish backdrop of Triptych - Studies from the Human Body (1970) could well be a tone of Dulux Vinyl Soft Sheen called "Orange Tropics" (pounds 11.99). In Study for Self-Portrait - Triptych (1985), Bacon may have gone for bulk with a 5-litre pot of Dulux Trade Matt Emulsion (pounds 24.99) in a colour called "Serenade". After all, anyone described as "the greatest British painter of this century" could certainly count himself as "trade".

It's a pretty safe bet that very few of us will be around for our 250th birthday. One exception is the philosopher Jeremy Bentham (1748-1832), the "father of utilitarianism", who will clock up his quarter-millennium tomorrow. Since 1850, the great man has sat in a handsome maple cabinet in University College, London, which he helped to create. He is dressed in light brown breeches, a dark brown jacket and white cravat and holds his walking stick (which he named "Dapple") in gloved hands. Sadly, the sage is sockless - they were pinched when he was lent to an exhibition in Essen, Germany, in 1990. However, textile experts believe his underwear to be the oldest in England. He is unlocked every morning by Michael Brady, Head Beadle at UCL: "I always say `Good Morning' but receive no reply. I wheeled him out for the 150th anniversary of the college where he was recorded as being `Present, but not voting'."

It is not known why Bentham took the decision to be preserved as an "auto- icon" after death, but it was probably a satirical gesture against the icons of church, law and aristocracy. All were institutions that Bentham, admirable fellow, insisted had a corrupting effect on society. His friend Dr Thomas Southwood Smith was responsible for producing the auto-icon. After dissection, Bentham's skeleton was padded with straw, cotton-wool and a bunch of lavender (to keep moths at bay). Though Smith attempted to preserve Bentham's head after his death, the results were unsatisfactory and a wax head was commissioned from a French modeller. It incorporates a pair of bright eyes, which the philosopher prudently purchased some years beforehand and would play with in absent-minded moments. Thought to be extremely lifelike, the wax head now beams genially from under a straw hat. Bentham's skull was kept in a box near the cabinet until 1990 when students from King's College briefly kidnapped it during their rag week. (According to one story, the head also disappeared in the Eighties and turned up in a left luggage locker in Aberdeen station.) To prevent such mishaps, it is now hidden from public view. "We hope to reunite his body with his head on 16 February," said Patrick Edwards, UCL's Head of Media Relations. "It will be a very big day for all utilitarians." However, the college's responsibilities towards Bentham go beyond the auto-icon. Along with looking after Bentham's corpse, University College is also preserving his corpus. Edited by a team of UCL academics, The Collected Works of Jeremy Bentham has currently reached volume 21 (Oxford, pounds 60). "There are another 47 on the way, which we aim to complete within 25 years," said Dr Philip Schofield. "Though he's one of our greatest thinkers, we have to work on a shoestring. In France or America, Bentham would be a national treasure."

What gastronomic plans do you have to celebrate this rather special evening? Don't tell me oysters. According to food expert Paul Levy, "the aphrodisiac reputation of oysters is doubtless based on their resemblance to female genitalia" (a likeness which had hitherto escaped me). Though indubitably delicious, the arousing qualities of the bivalve were recently pooh-poohed on TV by the great Rick Stein. Similarly, asparagus certainly looks the male part, but the pungent pong it imparts to the urine of the consumer is scarcely aphrodisiac. As for passion fruit, everyone knows that its name derives from the Passion of Christ.

According to Jane Grigson, your best bet for aphrodisiac success is that tough, yellow fruit, the quince. In her Fruit Book, she writes that the golden apple that Paris awarded to Aphrodite was actually a quince: "The fruit of love, marriage, fertility." She quotes some bittersweet lines written about the quince by a 10th century Arabic poet: "It has the perfume of a loved woman and the same hardness of heart." Unfortunately for tonight's festivities, the fruit is available only in autumn, but I was pleased to discover that Wilkin & Sons, "By Appt. to HM the Queen, Jam & Marmalade Manufacturers", produce both a Quince Conserve and a Quince Jelly in their Tiptree range. Though a little surprised to hear that they were making a legendary aphrodisiac ("I never heard that before"), the company kindly volunteered to send me a couple of jars. Now where's that runcible spoon?