The cultural history of sex has had a good run in recent years. We've had Rachel Maines's scholarly, startling, and hilarious history of the vibrator, The Technology of Orgasm, after which most male readers will have needed a period of fasting and prayer before rejoining the ladies. Michael Mason's The Making of Victorian Sexuality positively glittered with the shards of shattered prejudices, while solo sack-artists had their own lonely striving anatomised in Solitary Sex, an alarming history of masturbation from a history professor at Berkeley, in which the traditional fate of those who commit the horribile crimen of wanking (becoming feeble and blind, with before dying in a loony bin) was revealed to have been pseudonymously invented in the early eighteenth century. And (moving from the craftsman to his tool) A Mind of its Own, David Friedman's cultural history of the penis, gave us possibly the most erudite dick book ever written.

In his contribution to this corpus, Jonathan Margolis adopts a risky strategy. The territory of steam-powered vibrators, autonomous penises and solitary vice having been nobbled, he has moved into detailed physiology: specifically the spasms which