In the 1870s Edward Ballard, who was writing a book about pollution and working practices, visited and reported on several chemical companies in the area - Wallace, Forbes, and Hills as well as Blott and Percival Smith, both on Bow Common, and Crow at Barking Level. Ballard commented that all of these only used gas works liquor as their main raw material.
There were many more manufacturers than those visited by Ballard. By the 1860s London companies could not supply enough liquor and additional supplies came from gas works in many areas outside London. In some years the Colchester Gas Co sold all their liquor in 1868 to the Imperial Company who handled its sale on their behalf. At another time Colchester Co. sold their liquor to Simpson of Millwall who made sulphate of ammonia. The accounts of Lawes Agricultural Manure Company at Barking in the early 1870s gives some idea of the amount they were taking - 20 tons of ammonia from Hills.
Considerable quantities of ammoniacal liquor were bought from the early gas industry. It must be significant that most of it was bought by manufacturing chemists. Some, perhaps all, of them made ammonia salts. Most of them had works in east London. Despite the lack of records from the chemists themselves, it must be presumed that their products were sold to great range of industries. Thus gas companies were suppliers of raw materials to the chemical industry well before the development of coal tar dyes. The chemical industry itself was a major supplier of raw materials in this area and beyond.