There was once upon a time a Persian prince staying in Paris, who was taken to a very fashionable ball, that he might see a specimen of European civilization. I am not talking about a prince in the "Arabian Nights;" mine lived, I believe, in the time of Louis Philippe. The beautiful dancers wheeled round, their eyes brilliant with pleasure, in the arms of elegant cavaliers; one would have said that the whole of this airy troop, swaying to and fro in time to the lively flourishes of the music, was animated by one soul; everything seemed full of joy in that large and splendidly lit hall, and mothers secretly envied their daughters as they passed and re-passed before them. Our oriental alone scanned with a disdainful eye this youthful enjoyment.

When it was ended,--"How is this?" said he to his conductor; "did you not tell me that I was to see here the most distinguished families of Paris?"

"Certainly," replied the other; "among those young ladies who were just now dancing before you, there were at least twenty of the grandest heiresses of France."

"Young ladies who dance! Come, come! In my country we have dancers, but they are paid for it. Our wives are never permitted to dance themselves. That is all very well for the common people!"

Remember, when needful, the contempt of this Persian prince, my dear child; and let me beg of you, work for yourself. The dance of labor is worth quite as much as that of the ball-room, when you give your heart to it. It is even worth more, very often; and next time I will tell you why.

LETTER XXV.

CARBONIC ACID.

We are going to make acquaintance to-day with a new personage, who well deserves our attention. It is the child of oxygen and carbon, [Footnote: This is the name learned men have given to Charcoal.] though not in the same way that you are the child of your parents.

To tell you how it is made is more than I am able. It is a _gas_, or if you like the word better, it is an _air_; for when we say "gas," we mean "air;" only it is always a different sort of air from the air of the atmosphere, which learned people are not in the habit of calling _gas_. I cannot, therefore, show you _carbonic acid_ itself, for it cannot be seen any more than the air which fills an empty glass. But I can tell you where there is some, and you even probably know it by its effects, although you have never heard its name.