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What is a jouncer? According to the OED, “to jounce” is “to move violently up and down; to bump, bounce, jolt”. The playwright Simon Gray began jouncing while still in his pram, and carried on as a small boy in bed. The dedicated little jouncer accompanied his exertions with a keening noise that caused great irritation in the family. His father, a noted physician and surgeon, was particularly annoyed, since he needed all the sleep he could get in order to fulfil his extramarital duties in a variety of posh bedrooms. James Davidson Gray attached a hairbrush to his son’s pyjamas, knowing that the spikes would hurt him should he turn over in the night to jounce. The ruse wasn’t successful and the child was removed to a distant part of the house, out of Daddy’s earshot.

This latest instalment of Simon Gray’s continuing diary-cum-memoir is as entertaining as its predecessors. He still contrives to be funny on the subject of his increasing physical decrepitude — the liver he mistreated for half a century, and the lungs he will only stop abusing when he dies. His prostate is in disrepair, too, but he prefers not to think about it. Where once he consumed an excess of champagne, he now sips Diet Coke. His second wife, Victoria, is as doting as ever and the household is ruled over by an obese cat named Errol, another feline and a couple of dogs. Winter holidays are spent in Barbados, and in summer the family lives in Suffolk, giving Errol the opportunity to murder birds, fieldmice and other rodents who have the effrontery to stir him out of his lethargy.

The book opens in January 2004 and closes a year later. During that time, he has two plays staged — The Holy Terror, a new version of an earlier piece called Melon, and The Old Masters, which deals with the friendship between the art historian Bernard Berenson and the millionaire Joseph Duveen. One of the book’s most hilarious set-pieces is concerned with the first American production of The Holy Terror, directed by a man so drunk that when the actors bumped into the furniture in rehearsal, he insisted that the chairs and tables be taken away. The cast had trouble communicating, due to the fact that the lighting was dim to the point of near-darkness. All attempts to sack the inebriated lunatic failed, for reasons Gray reveals with absolutely perfect timing.

The Holy Terror was a failure in London, with its star, Simon Callow, receiving vindictive reviews. The Old Masters, under the direction of Harold Pinter, fared better and ran for several months. Describing Edward Fox’s bizarre performance as Berenson, Gray employs the word “eccentric”. You can say that again, but when Gray observes that Fox’s way of speaking is akin to plainsong, he is hitting the target. He has no reservations about Barbara Jefford in the role of Mrs Berenson; this great, undervalued actress illuminates every part she assumes.

There is a poignant section in the book devoted to the last months in the life of Alan Bates, the actor who shared in Gray’s success with his outstanding interpretations of the chronically self- obsessed heroes of Butley and Otherwise Engaged. He remembers as well a youthful infatuation with a fellow student at Westminster School, who died obscenely young. This memory, beautifully rendered, inspires him to contemplate the nature of being gay. He isn’t, of course, and I warmed to his diatribe against the illiterate, fashionable coinage “homophobia”. Why, he wonders, is the word Sodom preferred over Gomorrah? He likes the idea of someone being gomorrahed, and so do I.

Diaries give their writers the freedom to digress, and Gray’s digressions are as brilliant as they are idiosyncratic. An insomniac, he watches late-night movies on television, and marvels at the beauty and aplomb of the young Cary Grant. He has a DVD of one of his favourite films, the classic western Shane, and deplores the fact that people flock to see Peter Jackson’s versions of The Lord of the Rings, with their perpetual violence and nonsensical dialogue.

I hope that Gray is already jotting down his thoughts and insights for a forthcoming volume. Like Bennett, he writes with an audience in mind and his torrential sentences, containing as many clauses as in late Henry James, are set down with immense cunning and skill. Gray, the old jouncing semi-ruin, is an attractive if waspish romantic at heart. Let his liver, lungs and prostate be spared for many years to come.

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