How did Joseph Black help improve the bleaching of linen in Scotland?

Joseph Black contributed to the improvement of linen bleaching in Scotland by enhancing the effectiveness of the chemical agents used in the process. During the 18th century, the Scottish linen industry faced a crisis due to a significant rise in the price of potash, which was traditionally used for bleaching.

Black’s primary contribution was the discovery that the bleaching power of potash could be increased by adding lime to it. This finding was documented in his only substantial publication on an industrial process, titled "An Explanation of the Effect of Lime upon Alkaline Salts," which appeared in his colleague Francis Home’s 1771 work, Experiments on Bleaching.1

Additionally, Black served as an expert advisor to the Board of Trustees for Manufactures in Scotland, where he evaluated various proposals for industrial development, including new schemes for bleaching linen. His expertise in assessing the viability of such chemical processes made him a highly sought-after consultant for Scottish industrialists during the country's period of rapid industrialization.1