aid Tom merrily.

"Yes, go on," said the Vicar.

"Why is the face of the glass put in water, uncle?"

"To keep it wet and thoroughly clean. Dust or floating spores might
settle upon it, and then we should have specks. I want to get a surface
perfectly clear; and now, Tom, I want the four bottles I prepared
yesterday--fetch them down."

Tom ran up into the laboratory, and brought down four great stoppered
bottles, each of which bore a label duly lettered.

These he placed on the broad, table-like bench, and on being requested
hurried up-stairs again to fetch a large glass jar-shaped vessel, and a
graduated measuring-glass.

"Now," said Uncle Richard, "this process is a chemical experiment, but
upon reading it I felt that it was as good as a conjuring trick, and a
very grand one too. In fact it is good enough for a magician, for it is
a wonderful example of the way in which our chemists have mastered some
of the secrets of Nature."

"Bravo, lecturer!" said the Vicar. "Come, Tom, my boy, give him some
applause. Clap your hands and stamp your feet;" and the visitor led off
by thumping his umbrella upon the floor.

"Oh, very well," said Uncle Richard, laughing; "it shall be a lecture on
silver if you like--a very brief one, with a remarkable experiment to
follow."

"More applause, Tom," said the Vicar; and it was given laughingly.

"I have here," continued Uncle Richard, "immersed in distilled water--"

"Rain-water, uncle."

"Well, boy, rain-water is distilled by Nature, and then condensed from
the vapoury clouds to fall back upon the earth."

"Good," said the Vicar. "I am learning."

"Next," said Uncle Richard, "I have here a bottle marked A, containing
so many grains of pure potash, dissolved in so many ounces of water--a
strong alkaline solution in fact."

More applause.

"In this next bottle," continued Uncle Richard, "marked B, I have a
strong solution of ammonia."

"Another alkali?" said the Vicar.

"Exactly," said Uncle Richard. "In this bottle, marked C, a solution of
sugar-candy prepared with pure spirit. Can I have the pleasure of
offering you a glass, Vicar?"

"Oh no, thanks," was the reply. "I will not spoil the experiment by
satisfying my desire for good things."

"Will any other member of the audience?" said Uncle Richard merrily,
looking round at Tom.

"I won't, uncle, thankye," said the lad. "You might have labelled the
bottles wrongly."

"Wise boy," said the Vicar; "bu