diamonds.
I had seen this curious appearance before, but never so bright as it was
on that night.

"What is it, Tom?" said I, as my friend came forward and leaned over the
ship's bulwark beside me.

"It's blue fire, Bob," replied Tom, as he smoked his pipe calmly.

"Come, you know I can't swallow that," said I; "everybody knows that
fire, either blue or red, can't burn in the water."

"Maybe not," returned Tom; "but it's blue fire for all that. Leastwise
if it's not, I don't know wot else it is."

Tom had often seen this light before, no doubt, but he had never given
himself the trouble to find out what it could be. Fortunately the
captain came up just as I put the question, and he enlightened me on the
subject.

"It is caused by small animals," said he, leaning over the side.

"Small animals!" said I, in astonishment.

"Ay, many parts of the sea are full of creatures so small and so thin
and colourless, that you can hardly see them even in a clear glass
tumbler. Many of them are larger than others, but the most of them are
very small."

"But how do they shine like that, sir?" I asked.

"That I do not know, boy. God has given them the power to shine, just
as he has given us the power to walk or speak; and they do shine
brightly, as you see; but _how_ they do it is more than I can tell. I
think, myself, it must be anger that makes them shine, for they
generally do it when they are stirred up or knocked about by oars, or
ships' keels, or tumbling waves. But I am not sure that that's the
reason either, because, you know, we often sail through them without
seeing the light, though of course they must be there."

"P'raps, sir," said Tom Lokins; "p'raps, sir, they're sleepy sometimes,
an' can't be bothered gettin' angry."

"Perhaps!" answered the captain, laughing. "But then again, at other
times, I have seen them shining over the whole sea when it was quite
calm, making it like an ocean of milk; and nothing was disturbing them
at that time, d'ye see."

"I don' know _that_," objected Tom; "they might have bin a-fightin'
among theirselves."

"Or playing, may be," said I.

The captain laughed, and, looking up at the sky, said, "I don't like the
look of the weather, Tom Lokins. You're a sharp fellow, and have been
in these seas before, what say you?"

"We'll have a breeze," replied Tom, briefly.

"More than a breeze," muttered the captain, while a look of grave
anxiety overspread his countenance;