As a young man, he received his collegiate training in Mathematics at Trinity Hall, Cambridge,[2] as did his younger brother, Thomas, although the latter eventually graduated in Law.
After his father's inheritance, Salusbury bought a small house in London's Soho Square and, finding himself unable to pay off the rest of his debts worked as a fortune hunter, and according to court gossip, as a gigolo.
Unable to receive a position at court due to his father's reputation for intrigues, John travelled abroad as a companion to his cousin, Sir Robert Cotton, 3rd Baronet.
The two-year journey with Cotton ended in France, where Salusbury had received a position with the French court at Versailles and again served as a companion, this time to the young wife of the elderly Duc de Noailles with whom he probably had a romantic liaison.
Having exhausted his time at Versailles, in part due to the anti-English sentiment then in France, Salusbury returned to England, where he found his family's estates, Lleweni Hall and Bach y Graig mortgaged to the hilt by his brother who had taken out large loans to sustain his gambling debts in London.
Cotton was forced to pay a large indemnity to what were probably Jewish bankers, signified by Salusbury's daughter's early writings which indicated a significant amount of anti-semitic prose (she would later in life change her views and become literate in Hebrew).
During his tenure in Canada, he spent much of his time as a magistrate for the colony, finding life difficult and complaining in his diary that his crops were virtually worthless as they had to be shipped to London to be sold in accordance with the policy of mercantilism.
During Salusbury's remaining years his financial position and that of his brother were switched, and by 1759 he had begun to receive large payments from Thomas who was by then a high-ranking judge for the High Court of Admiralty.
This enabled John to live well and over the years he would entertain several personalities whom he met during his time in Nova Scotia, including Charles Lawrence, Jonathan Belcher and Edward Cornwallis.
John's legacy is perhaps best encapsulated in his journals, which thoroughly describe the daily life and problems encountered by both the colonists and the British government in the settlement of Nova Scotia.