, Willis; but do you know the weight of it you
carry on your shoulders?"

"Well, it cannot be very great, otherwise I should feel it."

"What do you say to a ton or so, old fellow?"

"If you wish me to believe that, you will have to explain how, where,
when, why, and wherefore."

"Very good. Willis; you have bathed sometimes?"

"Yes, certainly."

"In the sea?"

"Yes."

"Do you know what water weighs?"

"No, but I know that it is heavy."

"Well, a square yard of air weighs two pounds and a half, but a square
yard of water weighs two thousand pounds. Now, can you calculate the
weight of the water that is on your back and pressing on your sides
when you swim?"

"No, I cannot."

"You are not sufficiently up in arithmetic to do that, Willis?"

"No."

"Nor am I either, Willis; but let me ask you how it is that the waves
do not carry you along with them?"

"Because one wave neutralises the effect of another."

"Very good; but how is it that these ponderous waves, coming down upon
you, do not crush you to atoms by their mere weight?"

"Well, I suppose that liquids do not operate in the same way as
solids: perhaps there is something in our bodies that counterbalances
the effect of the water."

"Very likely; and if such be the case as regards water, may it not be
so also as regards air?"

"But I do not feel air; whereas, if I go into water, I not only feel
it, but taste it sometimes, and I cannot force my way through it
without considerable exertion."

"That is because you are organized to live in air and not in water.
You ask the smallest sprat or sticklebake if it does not, in the same
way feel the air obstruct its progress."

"But would the stickleback answer me, Master Fritz?"

"Why not, if it is polite and well bred?"

"By the way, Willis," inquired Jack, "do you ever recollect having
lived without breathing?"

"Can't say I do."

"Very well, then; had you felt the weight of the air at any given
moment, it must have produced an impression you never felt before, but
you have not, because circumstances have never varied. A sensation
supposes a contrast, whilst, ever since you existed, you have always
been subject to atmospheric pressure."

"Ah, now I begin to get at the gist of your argument. You mean, for
example, that I would never have appreciated the delicate flavor of
Maryland or Havanna, had I not been accustomed to smoke the
cabbage-leaf manufactured in Whitechapel."

"Precisely so;