Known from a lithograph of a silhouette by the artist of Sir Robert Peel. The lithograph was published by William Spooner, of 377 Strand, London, apparently during the Tate 1830s; there is a copy in the National Portrait Gallery and Mrs Peggy Hickman illustrates it in Two Centuries of Silhouette. (William Spooner was probably from the same family of engravers as C. Spooner, c. 1720-1767, a worker in mezzotint who reproduced mainly portraits, some of which were his own work).
Foskett mentions several artists of the Bouvier family (who were probably of French origin), including several recorded by Bénézit. One, who signed his work without an initial, was working c. 1804-1805. Another (Augustin or Augustus Jules Bouvier) is thought to have been born in London in c. 1825.
An engraver, H. Brocas (1765-1838), who had a son of the same name, may have been related to James Brocas. He worked in line, and engraved original views after his own drawings or paintings. Graves records a portrait by C. Brocas (probably a member of the family), sent in from Dublin and exhibited at the Royal Academy in 1821.
Jackson does not appear to have seen James Brocas's work, and since her book was published none appears to have corne to light. Both bust-length and full-length work are mentioned in the advertisement quoted above. Should any examples be discovered, they would show the sitters in the costume of the 1770s at the latest. Their style and technique remain a matter for conjecture. The use of crayons is mentioned; possibly Brocas worked in a style similar to the clare-obscure method used by Torond. Alternatively, since Brocas asked only half-a-crown each for bust-length profiles, he may have painted these in solid black.
Since Brocas worked as a painter in oils and a miniaturist, it is likely that he signed his work. Certainly no trade label of his is known.