In 1865 Young bought out his business partners and built second and larger works at Addiewell, near West Calder. It was a substantial industrial complex, in its time one of the largest chemical works in Scotland. In 1866 Young sold the concern to Young's Paraffin Light and Mineral Oil Company. Although Young remained in the company, he took no active part in it, instead withdrawing from business to occupy himself with yachting, travelling, scientific pursuits, and looking after the estates which he had purchased.