Hair of the dog

Q From Nicholas Brandes: I’ve heard that hair of the dog originates in an ancient cure for rabies, where the hair of the rabid dog is put into the wound as a supposed cure. Is this right? If so how did it morph into a remedy for a hangover?

A You have heard correctly.

The origin lies in ancient medical practice, which was based in part on sympathetic magic. The ancient Greek physician Hippocrates, often called the father of medicine, expressed it as “Like cures like”. If you had an ailment, it was argued, the cure would be found in some stuff that mimicked the symptoms. The same idea was expressed in the Latin similia similibus curantur and is the basis of homeopathy, developed by Samuel Hahnemann in the eighteenth century. If you were bitten by a snake, a medication incorporating snake venom was thought to cure the sickness. If bitten by a mad dog, applying a hair of the dog to the bite (sometimes roasted and made into a poultice with honey and herbs) would spare you the risk of rabies, because it was believed that every dog carried about with it an antidote to its own poison.

Hence the oldest and fullest expression of the idea, “the hair of the dog that bit me”. Its specific application to a morning-after dose of alcohol to relieve the effects of the previous night’s over-indulgence goes back at least to classical Greece. The aphoristic phrase “to drive out wine with wine” appears in a play by Antiphanes in the third century BC and in a work by Lucian of Samosata in the first century AD. It’s not quite so old in English:

What how fellow, thou knave,
I pray thee let me and my fellow have
A haire of the dog that bit us last night.
And bitten were we both to the braine aright.

A Dialogue Conteinyng the Nomber in Effect of all the Prouerbes in the Englishe Tongue, John Heywood, 1546.

As a young man, the famous diarist Samuel Pepys recorded being introduced to the remedy:

Up among my workmen, my head akeing all day from last night’s debauch. To the office all the morning, and at noon dined with Sir W. Batten and Pen, who would needs have me drink two drafts of sack to-day to cure me of last night’s disease, which I thought strange but I think find it true.

Diary, by Samuel Pepys, 3 Apr. 1661. Sack was a dry white wine imported from Spain and the Canaries.

It’s still as popular a saying as it was in the time of the ancient Greeks, though it isn’t always applied to alcohol:

Dunbar thinks laughter may have been favoured by evolution because it helped bring human groups together, which I hope many readers managed to do over the holiday weekend. But this morning there may be a need for a humorous “hair of the dog”. So today’s column offers you some medical humour with which to ease back into your particular salt mine.

Irish Times, 20 Mar. 2012.