A DRAWING LESSON.
For a moment Monsieur Dalize was disconcerted, and knew not what to say
in answer. Happily, Monsieur Roger came to his aid. He took the book
from Miette's hands, looked at the engraving, and said, quietly,--
"Why, certainly, my dear young friend, the gentleman who made that
drawing ought to know something about chemistry and physical science."
"How so?" said Miette, astonished.
"Why, if he did not know the laws of physical science and of chemistry,
he has, none the less, and perhaps even without knowing it himself,
availed himself of the results of chemistry and physical science."
Miette took the book back again, looked at the drawing with care, and
said,--
"Still, there are not in this drawing instruments or apparatus, or
machines such as I have seen in my brother's books."
"But," answered Monsieur Roger, smiling, "it is not necessary that you
should see instruments and apparatus and machines, as you say, to be in
the presence of physical phenomena; and I assure you, my dear child,
that this drawing which is under our eyes is connected with chemistry
and physical science."
Miette now looked up at Monsieur Roger to see if he was not making fun
of her. Monsieur Roger translated this dumb interrogation, and said,--
"Come, now! what does this drawing represent? Tell me yourself."
"Why, it represents two peasants,--a man and a woman,--who have returned
home wet in the storm, and who are warming and drying themselves before
the fire."
"It is, in fact, exactly that."
"Very well, sir?" asked Miette.
And in this concise answer she meant to say, "In all that, what do you
see that is connected with chemistry or physical science?"
"Very well," continued Monsieur Roger; "do you see this light mist, this
vapor, which is rising from the cloak that the peasant is drying before
the fire?"
"Yes."
"Well, that is physical science," said Monsieur Roger.
[Illustration]
"How do you mean?" asked Miette.
"I will explain in a moment. Let us continue to examine the picture. Do
you see that a portion of the wood is reduced to ashes?"
"Yes."
"Do you also remark the flame and the smoke which are rising up the
chimney?"
"Yes."
"That is chemistry."
"Ah!" said Miss Miette, at a loss for words.
Every one was listening to Monsieur Roger, some of them interested, the
others amused. Miette glanced over at her friend Paul.
"What do you think of that?" she asked.
Paul did not care to reply. Albert wished to speak, but he stopped at a
gesture from his father. Monsieur Dalize knew that the real interest of
this scene lay with Monsieur Roger, the scientist, who was already loved
by all this little world. Miette, as nobody else answered, returned to
Monsieur Roger.
"But why," she asked, "is that physical science? Why is it chemistry?"
"Because it is physical science and chemistry," said Monsieur Roger,
simply.
"Oh, but you have other reasons to give us!" said Madame Dalize, who
understood what Monsieur Roger was thinking of.
"Yes," added Miette.
And even Paul, with unusual curiosity, nodded his head affirmatively.
"The reasons will be very long to explain, and would bore you," said
Monsieur Dalize, certain that he would in this way provoke a protest.
The protest, in fact, came.
Monsieur Roger was obliged to speak.
"Well," said he, still addressing himself to Miss Miette, "this drawing
is concerned with physical science, because the peasant, in placing his
cloak before the heat of the fire, causes the phenomenon of evaporation
to take place. The vapor which escapes from the damp cloth is water, is
nothing but water, and will always be water under a different form. It
is water modified, and modified for a moment, because this vapor, coming
against the cold wall or other cold objects, will condense. That is to
say, it will become again liquid water,--water similar to that which it
was a moment ago; and that is a physical phenomenon,--for physical
science aims to study the modifications which alter the form, the color,
the appearance of bodies, but only their temporary modifications, which
leave intact all the properties of bodies. Our drawing is concerned with
chemistry, because the piece of wood which burns disappears, leaving in
its place cinders in the hearth and gases which escape through the
chimney. Here there is a complete modification, an absolute change of
the piece of wood. Do what you will, you would be unable, by collecting
together the cinders and gases, to put together again the log of wood
which has been burned; and that is a chemical phenomenon,--for the aim
of chemistry is to study the durable and permanent modifications, after
which bodies retain none of their original properties. Another example
may make more easy this distinction between physical science and
chemistry. Suppose that you put into the fire a bar of iron. That bar
will expand and become red. Its color, its form, its dimensions will be
modified, but it will always remain a bar of iron. That is a physical
phenomenon. Instead of this bar of iron, put in the fire a bit of
sulphur. It will flame up and burn in disengaging a gas of a peculiar
odor, which is called sulphuric acid. This sulphuric-acid gas can be
condensed and become a liquid, but it no longer contains the properties
of sulphur. It is no longer a piece of sulphur, and can never again
become a piece of sulphur. The modification of this body is therefore
durable, and therefore permanent. Now, that is a chemical phenomenon."
Monsieur Roger stopped for a moment; then, paying no apparent attention
to Paul, who, however, was listening far more attentively than one could
imagine he would, he looked at Miette, and said,--
"I don't know, my child, if I have explained myself clearly enough; but
you must certainly understand that in their case the artist has
represented, whether he wished to or not, the physical phenomenon and
the chemical phenomenon."
"Yes, sir," answered Miette, "I have understood quite well."
"Well," said Monsieur Dalize, "since you are so good a teacher, don't
you think that you could, during vacation, cause a little chemistry and
a little physical science to enter into that little head?" And he
pointed to Paul Solange.
The latter, notwithstanding the sentiment of respectful sympathy which
he felt for Monsieur Roger, and although he had listened with interest
to his explanations, could not prevent a gesture of fear, so pronounced
that everybody began to laugh.
Miette, who wished to console her good friend Paul and obtain his pardon
for her teasing, came up to him, and said,--
"Come, console yourself, Paul; I will let you take my portrait a dozen
times, as you did last year,--although it is very tiresome to pose for a
portrait."
[Illustration]
[Illustration]