hair of the dog or hair of the dog that bit one.
The same thing that caused the malady or trouble used as a remedy or a relief, especially alcoholic beverages drunk in the morning to cure a hangover.
Apparently people used to actually believe that if a dog bit you, its hair would cure you of the bite. It certainly wouldn't appeal to me to try to pluck a hair from any animal that had bitten me. On the other hand, if I could get someone else to do it, I might reap a small amount of revenge, though not so very much. The Phrase Finder seems to think that it was Scots who believed this. Being widely known as heavy drinkers, perhaps the highlanders dreamed this one up as an excuse for a pot or two of ale with breakfast.
The concept is one that is widely held, across cultures. Perhaps it appears in its most explicit forms in the fundamental principle of homeopathy: similia similibus, curantur or “likes are cured by likes.”
1. Whitney, William Dwight and Benjamin E. Smith. 1914. The Century dictionary and cyclopedia; with a new atlas of the world. A work of general reference in all departments of knowledge. New York: Century Co. Accessed from: http:// www.global-language.com/century/
2. Martin, Gary J., ed. 2001. The Phrase Finder. Sheffield Hallam University. Accessed August 26 2001 from http:// www.shu.ac.uk/ web-admin/phrases/.
3. Brewer, E. Cobham. Dictionary of Phrase and Fable. 1898. Bartlby.com, 2000. Accessed Sep 5 2001 from http://www.bartleby.com/.