Short answers, pulled from the story.
John Roebuck is best known for introducing leaden condensing chambers for the manufacture of sulphuric acid in 1746. This innovation allowed the acid to be produced on an industrial scale for the first time. He and Samuel Garbett then built a dedicated factory at Prestonpans in Scotland in 1749 to manufacture it commercially.
Roebuck agreed to pay James Watt's debts and provide him a workshop at Kinneil House in exchange for a two-thirds share in Watt's engine invention. The workspace became known as James Watt's Cottage. Roebuck later sold his share to Matthew Boulton to cancel a £1,200 debt.
John Roebuck was born in Sheffield, where his father ran a prosperous manufacturing business. He graduated as a Doctor of Medicine from the University of Leiden in 1742 and died in Edinburgh on the 17th of July 1794.
The Carron Company ironworks was founded in 1759 at Carron, Stirlingshire, by John Roebuck together with Samuel Garbett and several other partners including Ebenezer Roebuck, Thomas Roebuck, Benjamin Roebuck, and two men named William Cadell. The works held Royal Navy contracts until they were cancelled in 1773.
Financial difficulties caused by losses at the Carron ironworks, flooding at his Bo'ness colliery, and a failed attempt to manufacture alkali forced Roebuck to sell his stake. He transferred his two-thirds share in Watt's engine to Matthew Boulton in exchange for the cancellation of a £1,200 debt.
John Roebuck was elected a Fellow of the Royal Society of London in 1764. He was also a Fellow of the Royal Society of Edinburgh.