In 1832 Irishman John Kyan became the first person to patent a modern wood preservative, writes Mary Mulvihill
In an effort to protect his Ark from the Flood, Noah treated the timbers with pitch, and for thousands of years, pitch and tar remained the best available wood preservatives. This all changed in 1832, when Irishman John Kyan patented a new chemical preservative for wood.
Kyan's technique was soon used to protect building timbers and railway sleepers, rope and sailcloth. It won the British Admiralty's "seal of approval", and even featured in a song:
". . . Wood will never wear out, thanks to Kyan, thanks to Kyan.
"He dips in a tank any rafter or plank, and makes it immortal as Diane."
Kyan (1775-1850) had been familiar with the problem of rotting wood even as a young man. His father had owned Avoca copper mines in Co Wicklow, where timber supports frequently rotted in the damp shafts.
Kyan senior died penniless in 1804, after the mine's fortunes declined, and John went to work at an English chemical factory.
He started experimenting with wood preservatives in 1812, and found that impregnating timbers with "corrosive sublimate" (bichloride of mercury), gave the best result. He sent a block of his treated oak to the British Admiralty, who put it in a "fungus pit" for three years. The wood emerged in perfect condition in 1831, and Kyan patented his technique the following year.
"Kyanisation" quickly attracted public and commercial attention helped enormously when noted English scientist Michael Faraday lectured about it at the Royal Institution, 120 years ago this month on February 22, 1833.
The Anti-Dry Rot Company bought the rights, and built huge treatment tanks at various locations around London. Many large buildings, including the British Museum, were built using kyanised timber protected using the Irishman's process.
Kyan's timing proved perfect. This was the start of the great railway era, and railway companies started switching from stone sleepers (which, being brittle, frequently broke) to wooden ones. This meant they also needed a good wood preservative.
Although bichloride of mercury was expensive and corroded iron fittings, Kyan's process was widely used worldwide until the discovery of creosote in 1853. Produced by distilling coal gas, creosote was also costly, but kyanisation remained popular into the 1860s, especially in the USA.
John Kyan later emigrated to the USA, and he was developing a filter system for New York city's water works when he died there in 1850.
Kyan's technique is seldom used now. An internet Google search uncovered just one modern reference to it, by German timber researchers but the word "kyanisation" is still listed in the Oxford English Dictionary.
• Mary Mulvihill is the Science Journalist of the Year 2003. John Kyan is one of the many inventors featured in her new book, Ingenious Ireland: a County by County Exploration of Irish Mysteries and Marvels (Town House, €30)