John Howard Kyan, inventor of the ‘kyanising’ process for preserving wood, is born on November 27, 1774, in Dublin. His father, also John Howard Kyan, is the owner of valuable copper mines in County Wicklow. He is educated to take part in the management of the mines, but soon after he enters the company its fortunes decline, and in 1804 his father dies almost penniless.

For a time, Kyan is employed at some vinegar works at Newcastle upon Tyne, but subsequently removes to London. The decay of the timber supports in his father’s copper mines had already directed his attention to the question of preserving wood, and as early as 1812 he begins experiments with a view to discovering a method of preventing the decay. Eventually he finds that bichloride of mercury or corrosive sublimate, as it is commonly called, gives the best results and, without revealing the nature of the process, he submits a block of oak impregnated with the substance to the Admiralty in 1828. It is placed in the ‘fungus pit’ at Woolwich, where it remains for three years exposed to all the conditions favourable to decay. When taken out in 1831, it is found to be perfectly sound, and after further trials it still remains unaffected.

Kyan patents his discovery in 1832 (Nos. 8263 and 6309), extending the application of the invention to the preservation of paper, canvas, cloth, cordage, etc. A further patent is granted in 1836 (No. 7001).

The process attracts great attention. Michael Faraday chooses it as the subject of his inaugural lecture at the Royal Institution on February 22, 1833, on his appointment as Fullerian professor of chemistry. Dr. George Birkbeck gives a lecture upon it at the Royal Society of Arts on December 9, 1834, and in 1835 the Admiralty publishes the report of a committee appointed by the board to inquire into the value of the new method.

In 1836, Kyan sells his rights to the Anti-Dry Rot Company, an Act of Parliament being passed which authorises the raising of a capital of £250,000. Tanks are constructed at Grosvenor Basin, Pimlico, at the Grand Surrey Canal Dock, Rotherhide, and at the City Road Basin.

Among the early applications of the process is the kyanising of the palings around the Inner Circle, Regent’s Park, which is carried out in 1835 as an advertisement with small brass plates being attached to the palings at intervals stating that the wood has been submitted to the new process. The plates soon disappear, but the original palings still remain in good condition.

The timber used in building the Oxford and Cambridge Club, British Museum, Royal College of Surgeons, Westminster Bridewell, the new roof of the Temple Church, and the Ramsgate harbour works is also prepared by Kyan’s process. When wooden railway ties become general, a very profitable business for Kyan’s company is anticipated, and for a time these hopes are realised.

It becomes evident that iron fastenings cannot be used in wood treated with corrosive sublimate, on account of the corrosive action, and it is said that the wood becomes brittle. The salt is somewhat expensive and Sir William Burnett‘s method of preserving timber by zinc chloride, and afterwards the application of creosote for that purpose, proves severe competitors. Doubts begin to be expressed as to the real efficiency of kyanising, and the process gradually ceases to be employed.

John Kyan dies on January 5, 1850, in New York City, where he is engaged on a plan for filtering the water supplied to that city by the Croton Aqueduct.