“Visible shapes, in the likeness of man? As visible and yet as tangible as that sunbeam?”

“Rather!”

“You allow that the camera can see them if we can?”

Pocket allowed it like the man he was being made to feel; the concession gave him a generous glow. Promotion had come to him by giant leaps. He felt five years older in fewer minutes.

“Then,” cried the doctor, with further flattery in his air of triumph, “then you admit everything! You may not see these images, but I may. I may not see them, but my lens may! Think how much that glass eye throws already upon the retina of a sensitised film that our living lenses fail to throw upon ours; think of all that escapes the eye but the camera catches. Take two crystal vases, fill one with one acid and the other with another; one comes out like water as we see it; the other, though not less limpid in our sight, like ink. The eye sees through it, but not the lens. The eye sees emptiness as though the acid itself were pure crystal; the lens flings an inky image on the plate. The trouble is that, while you can procure that acid at the nearest chemist’s, no money and no power on earth can summon or procure at will the spirit which once was man.”

His voice was vibrant and earnest as it had been when Pocket heard it first an hour earlier in the Park. It was even as passionate, but this was the passion of enthusiastic endeavour. If the man had a heart at all, it was in this wild question without a doubt. Even the schoolboy perceived this dimly. There was something else which had become clearer to him with each of these later remarks. Striking as they seemed to him, they were not wholly unfamiliar. The ring of novelty was wanting to his ear.

Suddenly he exclaimed, “I knew I knew your name!”

“You do know it, do you?”

Baumgartner spoke ungraciously, as though the announcement was discounted by the interruption it entailed.

“It was in connection with the very book I mentioned. I knew I had come across it somewhere.”