In 1828, Foss purchased a chemist shop in Sydney from
apothecary John Tawell; Foss would go on to own several more pharmaceutical and grocery stores in the next two decades. In 1844, Foss established the Pharmaceutical Society of New South Wales with a few pharmacists based in Sydney. In 1859, Foss and his son Thomas Ambrose set up a wholesale drug store, Foss Son Company. Foss was also a landowner. In 1833, he and his first wife purchased the Hereford House in
Glebe; three years later, in 1836, he built a house called Forest Lodge (demolished 1912) after which the Sydney suburb
Forest Lodge is named. In 1838, he built Carey Cottage on 18 Ferry Street, having bought land in Hunters Hill from Tawell. ==Personal life==