An Essay on the Law of Bailments, and the translation of an Arabian Poem, on the Mohammedan Law of Succession to the Property of Intestates, to the latter of which undertakings he was incited by his views of preferment in the East, testified his industry in the pursuit of his legal studies; while, on the other hand, several short poems evinced, from time to time, his intended relinquishment of the tuneful art to be either impracticable or unnecessary.
In the summer of 1782 the interests of one of his clients led him again to Paris, from whence he returned by the circuitous route of Normandy, and the United Provinces. In the spring of this year he had become a member of the Society for Constitutional Information. A more equal representation of the people in parliament was at this time the subject of general discussion, and he did not fail to stand forward as the strenuous champion of a measure which seemed likely to infuse new spirit and vigour into our constitutional liberties. His sentiments were publicly professed in a speech before the meeting assembled at the London Tavern, on the 28th of May; and he afterwards gave a wider currency to them from the press. He maintained that the representation ought to be nearly equal and universal; an opinion in which few would now be found to coincide; and which, if he had lived a little longer, he would probably himself have acknowledged to be erroneous. At Paris, he had written a Dialogue between a Farmer and a Country Gentleman on the Principles of Government, and it was published by the Society. A bill of indictment was found against the Dean of St. Asaph, whose sister he afterwards married, for an edition printed in Wales; and Jones avowed himself the author.
In the beginning of 1783 appeared his translation of the seven Arabian poems, suspended in the temple at Mecca about the commencement of the sixth century.
In the March of this year, he was gratified by the long desired appointment to the office of judge in the supreme court of judicature, at Fort William, in Bengal, which was obtained for him through the interest of Lord Ashburton; and he received the honour of knighthood usually conferred on that occasion. The divisions among his political friends, after the decease of that excellent nobleman, the Marquis of Buckingham, afforded him an additional motive for wishing to be employed at a distance from his country, which he no longer hoped to see benefited by their exertions. He was immediately afterwards united to Anna Maria Shipley, the daughter of the Bishop of St. Asaph, a learned and liberal prelate. His attachment to this lady had been of long continuance, and he had been waiting only for an honourable independence before he could resolve to join the fortunes of one so tenderly beloved to his own.