Messrs Bramwell
c.1700 The first attempt was made in the Newcastle area to manufacture a compound of cyanogen (to make Prussian Blue). Afterwards the apparatus was moved from Gateshead to Corbridge but the result was not commercially successful.
The apparatus was taken over by a Mr. Simpson, who ultimately succeeded in perfecting the process in works erected at Elswick. Mr. Simpson manufactured Prussian and other kinds of blue colours. After Simpson died the manufacture was removed to Heworth, where Messrs. Bramwell carried on the works since 1768.
Mr. Bramwell introduced various improvements in the manufacture of this salt, employing closed pots in which the fused materials are worked by machinery, and in substituting sulphate of potash for the more expensive potashes
1844 Bramwell attempted to produce cyanogen from the nitrogen of the air at these works - the chemical process was successful but the manufacture was not continued
By 1860 demand had fallen substantially, partly because of the American civil war and partly from the introduction of the aniline colours.