Although unambitious and showing no interest in wealth or power James Hutton acquired considerable wealth through his business interests.
He was partner in a successful and profitable sal ammoniac chemical works. Hutton devisied the manufacturing process with his business partner James Davie, involving soot collected on contract from Edinburgh’s chimney sweeps (known as tronmen). This was a pioneer of industrial chemistry. Sal ammoniac is ammonium chloride, a white soluble crystalline salt, used than for dyeing and working with brass and tin and as smelling salts. Prior to this, all the sal ammoniac used in Britain was imported from Egypt. It is now used in dry cell batteries.
Hutton also owned and rented-out houses and shops in Edinburgh, employing a manager (or factor), to oversee them
He experimented on developing a red dye for turkey red using the plant Rubia tinctoria (madder), which he grew either at Slighhouses or Edinburgh. He sent all this work to a manufacturer in Glasgow with success. One can only assume that he profited financially from this.