land
and sea--to say nothing of the prospect of supper--all tended to induce
a peaceful and forbearing spirit.

"Well, now," said Robin, continuing a subject which often engaged their
intellectual powers, "it seems to me simple enough."

"Simple!" exclaimed Johnson, with a half-sarcastic laugh, "w'y, now, you
an' the doctor 'ave tried to worrit that electricity into my brain for
many months, off an' on, and I do believe as I'm more muddled about it
to-night than I was at the beginnin'."

"P'r'aps it's because you hain't got no brains to work upon," suggested
Slagg.

"P'r'aps it is," humbly admitted the seaman. "But look here, now,
doctor," he added, turning to Sam with his brow knotted up into an agony
of mental endeavour, and the forefinger of one hand thrust into the palm
of the other,--"look here. You tells me that electricity ain't a
substance at all."

"Yes, that's so," assented Sam with a nod.

"Wery good. Now, then, if it ain't a substance at all, it's nothin'.
An' if it's nothin', how can you go an' talk of it as somethin' an' give
it a name, an' tell me it works the telegraph, an' does all manner of
wonderful things?"

"But it does not follow that a thing must be nothing because it isn't a
substance. Don't you see, man, that an idea is something, yet it is not
a substance. Thought, which is so potent a factor in this world, is not
a substance, yet it cannot be called nothing. It is a condition--it is
the result of brain-atoms in action. Electricity is sometimes described
as an `invisible imponderable fluid,' but that is not quite correct,
because a fluid is a substance. It is a better definition to say that
electricity is a _manifestation of energy--a result of substance in
action_."

"There, I'm muddled again!" said Johnson, with a look of hopeless
incapacity.

"Small blame to you, Johnson," murmured Slagg who had done his best to
understand, while Stumps sat gazing at the speakers with an expression
of blank complacency.

"Look here, Johnson," said Sam, "you've often seen men shaking a carpet,
haven't you?"

"In coorse I have."

"Well, have you not observed the waves of the carpet that roll along it
when shaken!"

"Yes, I have."

"What are these waves?"

"Well, sir, I should say they was the carpet," replied Johnson.

"No, the waves are not the carpet. When the waves reach the end of the
carpet they disappear. If the waves were the carpet, the carpet would
disappear. The sa