He, Bertheroy, had modestly declined to adjudicate, for the fragment submitted to him bore traces of so slight a character, that analysis became impossible.

Thus he was unwilling to make any positive pronouncement.

But his opinion was that one found oneself in presence of some unknown powder, some new explosive, whose power exceeded anything that had hitherto been dreamt of.

He could picture some unknown _savant_, or some ignorant but lucky inventor, discovering the formula of this explosive under mysterious conditions.

And this brought him to the point he wished to reach, the question of all the explosives which are so far unknown, and of the coming discoveries which he could foresee.