“You see,” said the director, addressing the Count d’Artigas.  “The idea of his invention never leaves him.”

“And it will die with him,” affirmed the attendant.

“Couldn’t you, Gaydon, get him to talk about his fulgurator?” asked his chief.

“I will try, if you order me to do so, sir.”

“Well, I do order you, for I think it might interest the Count d’Artigas.”

“Certainly,” assented the Count, whose physiognomy betrayed no sign of the sentiments which were agitating him.

“I ought to warn you that I risk bringing on another fit,” observed Gaydon.

“You can drop the conversation when you consider it prudent.  Tell Thomas Roch that a foreigner wishes to negotiate with him for the purchase of his fulgurator.”

“But are you not afraid he may give his secret away?” questioned the Count.

He spoke with such vivacity that Gaydon could not restrain a glance of distrust, which, however, did not appear to disturb the equanimity of that impenetrable nobleman.

“No fear of that,” said the warder.  “No promise would induce him to divulge his secret.  Until the millions he demands are counted into his hand he will remain as mute as a stone.”

“I don’t happen to be carrying those millions about me,” remarked the Count quietly.

Gaydon again touched Roch on the shoulder and repeated: 

“Thomas Roch, here are some foreigners who are anxious to acquire your invention.”

The madman started.

“My invention?” he cried.  “My deflagrator?”

And his growing animation plainly indicated the imminence of the fit that Gaydon had been apprehensive about, and which questions of this character invariably brought on.

“How much will you give me for it—­how much?” continued Roch.  “How much—­how much?”

“Ten million dollars,” replied Gaydon.

“Ten millions!  Ten millions!  A fulgurator ten million times more powerful than anything hitherto invented!  Ten millions for an autopropulsive projectile which, when it explodes, destroys everything in sight within a radius of over twelve thousand square yards!  Ten millions for the only deflagrator that can provoke its explosion!  Why, all the wealth of the world wouldn’t suffice to purchase the secret of my engine, and rather than sell it at such a price I would cut my tongue in half with my teeth.  Ten millions, when it is worth a billion—­a billion—­a billion!”

It was clear that Roch had lost all notion of things, and had Gaydon offered him ten billions the madman would have replied in exactly the same manner.

The Count d’Artigas and Captain Spade had not taken their eyes off him.  The Count was impassible as usual, though his brow had darkened, but the captain shook his head in a manner that implied plainly:  “Decidedly there is nothing to hope from this poor devil!”

After his outburst Roch fled across the garden crying hoarsely: