“You were wise in that,” said the Minister, drawing a deep breath. “Now let us go and look at the ruins.”

As they neared the spot the official’s astonishment at the extraordinary destruction became greater and greater. The rock had been rent as if by an earthquake, to the distance of hundreds of yards.

“You say,” said the Minister, “that the liquid is perfectly safe until evaporation takes place.”

“Perfectly,” answered Lambelle. “Of course one has to be careful, as I told you, in the use of it. You must not get a drop on your clothes, or leave it anywhere on the outside of the bottle to evaporate.”

“Let me see the stuff.”

Lambelle handed him the bottle.

“Have you any more of this in your laboratory?”

“Not a drop.”

“If you wished to destroy this, how would you do it?”

“I should empty the bottle into the Seine. It would flow down to the sea, and no harm would be done.”