Newman was enlightened on this point later.

Even Valentin did not quite seem master of his wits; his vivacity was fitful and forced, yet Newman observed that in the lapses of his talk he appeared excited.

His eyes had an intenser spark than usual.

The effect of all this was that Newman, for the first time in his life, was not himself; that he measured his movements, and counted his words, and resolved that if the occasion demanded that he should appear to have swallowed a ramrod, he would meet the emergency.
After dinner M.de Bellegarde proposed to his guest that they should go into the smoking-room, and he led the way toward a small, somewhat musty apartment, the walls of which were ornamented with old hangings of stamped leather and trophies of rusty arms.

Newman refused a cigar, but he established himself upon one of the divans, while the marquis puffed his own weed before the fire-place, and Valentin sat looking through the light fumes of a cigarette from one to the other.
"I can't keep quiet any longer," said Valentin, at last.