Jacob is best known for his legal writings and was very influential in the field of law, but he also published literary works of the satirical, farcical, and pornographic bent. He also had the honor of being named a dunce in Pope's The Dunciad, likely for his "devotion to a culture of litigation that Pope deplored." His most successful work was A New Law Dictionary, which went through multiple editions; the publisher John Murray acquired a 160th share on 24 June 1807 at a cost of £13, suggesting a total value of £2080. DNB: "It was the smallest fraction of a copyright which Murray bought that day, but the most expensive, showing how valuable Jacob's work remained over sixty years after his death." Published many, many works for Lintott and Curll.