Thomas left the Bromley mill in about 1827. Nothing more has been discovered about the family until Frank Hills began to contact the London gas companies from the Deptford Chemical Works in the early 1830s. This is the works that was owned by Beneke and has already been described.
By the mid-1830s several of the London gas companies were minuting approaches from Frank Hills who offered to sell acids, buy tar or ammoniacal liquor and to manufacture ammonia salts for them. The range of these offers seems to show that he saw the gas industry as a fruitful source for exploitation. Gas companies, immersed in the problems of manufacture and distribution, were probably happy to leave chemical investigation to others. It was a niche into which several chemists tried to put themselves, none more assiduously than Frank.
Frank Hills rented the Deptford Chemical Works from Frederick Beneke. How far Frank Hills took over his chemical business can be only be speculated. The Beneke family lived in Denmark Hill, in Camberwell. Frank lived nearby in North Terrace, Camberwell.
In 1836 the London and Greenwich Railway was built across Deptford Creek, and included a gas works alongside the line on a site next to the Deptford Chemical Works. Frank Hills was later to say that it was in this gas works that he experimented on gas industry wastes. It was said that when the gasworks became independent of the railway that Frank provided a mortgage on it. If so, he had some claims there.
Frank undertook a great deal of research at Deptford. It was said that he was 'always experimenting in the laboratories and the engineering workshops'. He claimed to have experimented on gas works wastes there with a Rev. Dale - although later information from the South Met. Gas Company cited a German chemist, a Mr. Baufe, who worked for him. While testing the impurities of a batch of guano, he discovered a means of extracting iodine. Henceforth the firm did this industrially. He refined saltpetre by double decomposition - by using nitrate of soda and muriate of potash.
Sulphur was also refined at Deptford and sold to Kentish hop growers.
In the early 1840s the Hills' business expanded to include a short lived chemical works at Battersea. It is not known if the family owned the Hill's Chemical Works in Wandsworth which failed and was subsumed into Wandsworth Gas Works where the plant was used to make sulphate of ammonia. In this context it might be noticed that Arthur Hills lived in the Norwood area.