The Dashing White Sergeant
Edward Linley Sambourne (1844-1910)
Wood engraving
Punch (11 February 1882): 71
Punch’s Fancy Portraits No. 70
“And I will be your — Ballantine.”
According to Wikipedia, Serjeant William Ballantine SL (1812-1887), served as a Serjeant at Law, which permitted him to wear a white cap of that rank. He decided not to cross-examine the Prince of Wales in a famous divorce case, thereby preventing the Prince from perjuring himself and embarrassing the royal family. He lost the case.