William Murdoch

William Murdoch (sometimes spelled Murdock) (August 21, 1754 - November 15, 1839) was a Scottish engineer and inventor. He was employed by the firm of Boulton and Watt and worked for them in Cornwall as a steam engine erector for ten years, spending most of the rest of his life in Birmingham. He was the inventor of gas lighting in the early 1790s and coined the term gasometer. In addition to gas he made a number of innovations to the steam engine, including the sun and planet gear and D slide valve, invented the steam gun and pneumatic tube message system, worked on the first British paddle steamer to cross the English Channel, built a prototype steam locomotive in 1784 and made a number of discoveries in the field of chemistry. He remained an employee of Boulton and Watt until the 1830's and his reputation as an independent inventor has tended to be obscured by the reputations of those two men and the firm they founded.

Chemistry Discoveries

In addition to his mechanical work Murdoch also experimented in the field of chemistry and made a number of discoveries. One such was the discovery, first recorded in 1784, of iron cement made from sal ammoniac, or ammonium chloride and iron filings, apparently discovered when Murdoch observed that these 2 components had accidentally mixed in his tool bag and formed a solid mass. This iron cement was used to fix and harden the joints of steam engines, thus creating a hard durable seal.

Related Topics:
Iron - Cement - Sal ammoniac - Ammonium chloride

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Another discovery, and the first for which Murdoch took out a patent was that of

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The art or method of making from the same materials and by the same processes entirely new copperas, vitriol, and different sorts of dye or dying stuff, paints and colours, and also a composition for preserving the bottoms of all kinds of vessels and all wood required to be immersed in water, from worms, weeds, barnacles, and every other foulness which usually does or may adhere thereto.

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This patent was filed in 1791 and although it was not developed at the time this can be seen as the first step in the development of aniline dyes and coatings.

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British Isinglass

In1795 Murdoch developed a replacement for Isinglass, a precipitate made from sturgeon used in the clarifying of beer to remove impurities, which had to be imported from Russia at great expense. Murdoch's replacement was made from dried Cod and was much cheaper than the 25 shillings a pound which Isinglass cost. This cost saving was so attractive that the Committee of London Brewers paid £2000 for the right to use his invention.

Related Topics:
1795 - Isinglass - Sturgeon - Russia - Cod - Shillings - Pound

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Murdoch's Isinglass replacement was so effective that in a court case brought by the British Customs and Excise Authorities, the noted Chemist, Sir Humphry Davy in answer to a question on whether it was "proper to be used for the purpose of fineing beer" testified that:

Related Topics:
Customs and Excise - Humphry Davy

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I believe it is if properly prepared - it is the same substance as Isinglass.

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Use of Murdoch's "Isinglass made of British fish" continued and played an important role in reducing British brewers reliance on imported raw materials.

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