The reference here to "the boa-constrictor trick" is little-used anymore, but it means to terrify one's victim so as to render him inanimate and then win the game.  Pétroleuses were rumored arsonists blamed for burning down much of Paris with Molotov coctails in 1871.

The caption reads: "A 'Pétroleuse,' bent evidently on no good; does the boa-constrictor trick, and swallows her blanket."  From Judy, Or The London Serio-Comic Journal, 1872.