t, by the way, where's the lump of
beaten-out silver to be affixed to the glass?"

"Here it is," said Uncle Richard, laying his hand upon the stopper of
the fourth bottle, which held the same quantity of liquid as the others.

"But that's clear water," said Tom.

"Yes, clear distilled water, but not alone. It contains a great deal of
silver."

"Whereabouts, lecturer?" said the Vicar.

"In solution," said Uncle Richard gravely. "Here we have one of the
wonders of science laboriously worked out by experiment, and when
discovered simplicity itself. Tom, suppose I take a piece of bright
clear iron and leave it out exposed to all weathers, what happens?"

"Gets rusty," said Tom.

"Exactly; and what is rust?"

"Red," said Tom.

"So is your face, Tom, for giving so absurd an answer."

"Yes, uncle," said Tom frankly. "I don't quite know."

"Oxide of iron," said the Vicar.

"Oh yes," cried Tom eagerly; "I'd forgotten."

"Well," said Uncle Richard, "the oxide of iron is Nature's action upon
the iron. Man produces iron by heat from the ore, but unless great care
is used to protect it from the action of the atmosphere, it is always
going back to a state of nature--oxidises, or goes back into a salt of
iron. That by the way; I am not dealing with a salt of iron but with a
salt of silver. There it is, so many grains of a salt of silver, which
looked like sugar-candy when I wetted it in the water, and, as you see
now, here it is a perfectly colourless fluid. There, I have nearly done
talking."

"More applause, Tom," said the Vicar merrily.

"Come, that's hardly fair," retorted Uncle Richard. "What would you say
to us if we applauded when you said one of your sermons was nearly at an
end?"

"But we did not applaud the announcement that you had nearly done," said
the Vicar, "but the fact that the experiment was nearly at hand."

"Yes; that's it, uncle. Go on, please," cried Tom.

"Very well then: my experimental magic trick is this," continued Uncle
Richard. "I am about not to change a metal into a salt, but a salt--
that salt in solution in the water--back into a metal--the invisible
into the visible--the colourless water into brilliant, flashing,
metallic silver."

"The cannon-ball changed from one hat to the other is nothing to that,
Tom Blount," said the Vicar; "but we are the audience; let's be
sceptical. I'll say it isn't to be done."

"Oh yes," said Tom seriously. "If uncle says he'll do it,