I also was much puzzled, and inclined to think with Jack that it
must be phosphoric light; of which luminous appearance we had seen
much while on our voyage to these seas. "But," said I, "there is
nothing to hinder us from diving down to it, now that we are sure
it is not a shark."

"True," returned Jack, stripping off his clothes; "I'll go down,
Ralph, as I'm better at diving than you are. Now then, Peterkin,
out o' the road!" Jack stepped forward, joined his hands above his
head, bent over the rocks, and plunged into the sea. For a second
or two the spray caused by his dive hid him from view, then the
water became still, and we saw him swimming far down in the midst
of the green object. Suddenly he sank below it, and vanished
altogether from our sight! We gazed anxiously down at the spot
where he had disappeared, for nearly a minute, expecting every
moment to see him rise again for breath; but fully a minute passed,
and still he did not reappear. Two minutes passed! and then a
flood of alarm rushed in upon my soul, when I considered that
during all my acquaintance with him, Jack had never stayed
underwater more than a minute at a time; indeed seldom so long.

"Oh, Peterkin!" I said, in a voice that trembled with increasing
anxiety, "something has happened. It is more than three minutes
now!" But Peterkin did not answer and I observed that he was
gazing down into the water with a look of intense fear mingled with
anxiety, while his face was overspread with a deadly paleness.
Suddenly he sprang to his feet and rushed about in a frantic state,
wringing his hands, and exclaiming, "Oh, Jack, Jack! he is gone!
It must have been a shark, and he is gone for ever!"