Neither Decoud nor Mrs Gould knows of Charles' dynamite plan, and yet Decoud's gesture, referring specifically to the people of the "gorge of San Tomé," directly references it, as does Mrs Gould's innocent suggestion that he direct the gesture and accompanying appeal to her husband. The reader, who does know of the dynamite plan, is being deliberately teased by the narrator here. It is part of a long progression in which the novel builds suspense toward spectacular scenes of battle and destruction, all leading to a brilliantly-managed anticlimax in which none of these scenes occur. See my note introducing Chapter 3-10.

On the surface, of course, Decoud is talking about a Monterist takeover of the mine, which would have the same annihilating effect on Mrs Gould's altruist ventures. He is thus reminding Mrs Gould that altruism depends upon material progress and cannot function under primitive dictatorial conditions. It is a very shrewd and conscious thrust by the watchful Decoud, who, alone in the novel, understands the inherent selfishness underlying the altruist ideal, and who is really appealing to Mrs Gould's self-interest under cover of threatening the masses.