He received a commercial education at the Philological School, Marylebone, and spent a short time in a merchant's office in London; but then took a post in the printed-book department in the British Museum.
His best-known cases were the trial of Manning in 1849; of Franz Müller, for the murder of Mr. Briggs, in October 1864; the Overend and Gurney prosecution in 1869; the indictment of Arthur Orton the Tichborne claimant, in 1873–4; and Whistler v. Ruskin in November 1878.
[1] In politics Parry was a Radical—or advanced liberal—and at the time of the first Chartist movement he sympathised with some of their moderate views, and knew many of their leaders: William Lovett mentioned assistance received from him.
[1] Parry was twice married: first, to Margaret New, who died on 13 September 1856; and afterwards to Elizabeth Mead, daughter of Edwin Abbott; she predeceased him by a few hours.
He had two sons, of whom the elder, John Humffreys, an actor, died in 1891; the second was Edward Abbott Parry, judge and man of letters.