as possible! After this, you need not be surprised that people should look fagged and exhausted next morning. What astonishes me is that they are not obliged to lic in bed altogether, after treating their poor lungs to such an entertainment. And even if you have spared your legs, you are not much better off, as you are sure to find out in time, especially if the thing is repeated too often.

When I told you just now that the dance of labor was worth as much as the dance of the ball-room, was I right or wrong? What do you say yourself?

I could repeat the same of theatres-places of enter tainment specially adapted for impoverishing the blood, and ruining the health of the happy mortals who go there, evening after evening, to purchase at the door the right of filling their lungs with carbonic acid, not to speak of other poisons. You must see clearly that such places as those are not fit for little lungs as dainty as yours; and this may help you to submit with a good grace when you see people going there without you. Grown-up people escape morcover, because the human machine possesses a strange clasticity, which enables it to accommodate itself-one scarcely knows how-to the sometimes very critical positions in which its lords and masters place it without a thought. But to do this, it is well that it should be thoroughly formed and established; for you run a risk of injuring it for ever, if you misuse it too early in life. Tell this to your dear schoolboy brother, when he wants to smoke his cigar like a man. If his lungs could speak, they would call out to him that it was very hard upon them, at their age, to be so treated, and that he ought at any rate to wait till they had passed their examinations!

But I must not get into a dispute with so important an individual, by throwing stones into a garden which

is not under my care. For you, my dear child, the moral of this day's lesson-which to my mind is much more alarming than a hobgoblin tale, since it concerns the realities of every-day life—is clear; and it is this:

Seek your amusements as far as possible in the fresh air. In the summer, when the lamp is lit, bid your ramma a sweet good-night, and go to bed. In the winter do not wait till there is a great quantity of carbonic acid in the room where the grown-up people are sitting, before you retire to your own like a reasonable girl, anxious not to do mischief to that valuable and indefatigable servant, the poor blood! Not to mention that if she were to injure him too much, she would have to bear his grumbling for the rest of her life. We cannot change him as we change other servants.

LETTER XXVI.

ALIMENTS OF COMBUSTION.

WE have spent a very long time, my dear child, over the little fire, which goes on burning secretly in every one of us, quietly devouring what little girls eat with such a good appetite, quite unsuspicious of what they are doing it for. However, if I mean to finish the history of our mouthful of bread, I must push on to its last chapter.

The whole of what we eat is not burnt, as you may casily suppose; for, if it were, what would the blood have left to feed the body with, and to repair in due proportion the continual destruction or waste which goes on in our organs? Our food, or "aliments," as the general collection of different sorts of food is called, are divided into two very distinct sets: some, which are destined to be burnt, and which are called aliments of combustion; others, which are destined to nourish the body, and which are called aliments of nutrition. I have to tell you now about these last, and you will find their history by no means uninteresting.

Learned men having detected, beyond the possibility of a doubt, the existence of these two sorts of aliments, one is tempted to think they ought to have made it known to the cooks, and that ever since so important a discovery, the dishes on all well-regulated tables should have been arranged accordingly; aliments of combustion

on one side, aliments of nutrition on the other. It cannot be enough merely to give your guests a treat; you ought to provide them with everything necessary for the proper fulfilment of the claims within; and if you give some nothing but combustibles, leaving the others no share of fuel, how will they be able to manage? No. body thinks about this, however; not even cooks, to begin with, who, as far as fire is concerned, find. they have had quite enough to do with it in their cooking; and as for the guests, when they have had their dinner they go away satisfied, as a matter of course, quite as well provided for as if the mistress of the house had made her calculations, pen in hand, while writing out the bill of fare, with a view to combustion and nutrition. Now, how is that?

It is because the two sorts of aliments are, for the most part, met with together in everything we eat, so that we swallow them at once in one mouthful; and have therefore no need to trouble ourselves further on the subject. There is our bit of bread, for instance. What is bread made of? Of flour. Bread, then, must contain all that was previously in the flour. Very good. Now I will teach you how to discover in flour the ali ment of combustion on the one hand, and the aliment of nutrition on the other.

Take a handful of flour, and hold it under a small stream of water; knead it lightly between your fingers. The water will be quite white as it leaves it, carrying away with it a fine powder, which you could easily collect if you were to let the water run into a vase, where the powder would soon settle to the bottom. That powder is starch-the same starch as washerwomen use for starching linen, and which our grandfathers employed in powdering their wigs. You had some put on

your own hair one day when you were dressed up as a court-lady of olden time. Now, starch is an excellent combustible. People have succeeded, by means which I will not offer to detail here, in ascertaining almost exactly what it is made of, and they have found in it three of our old acquaintances, oxygen, hydrogen, and carbon, combined together in such proportions that 100 ounces of starch contain as follows:

I give you the calculation in round numbers, so as not to burden your memory with fractions; and I will do the same with the other sums I shall have to go through to-day, this being, let me tell you, an arithmetical day. Besides, I could scarcely take upon myself to warrant the absolute correctness of those very precise fractions people sometimes go into. Even our learned friends squabble now and then as to which is right or wrong over the 100th part of a grain, more or less, in making out their balance, and you and I will not offer to decide between them. I always think we have accomplished wonders in getting even near the mark, and with their permission we will stop there.

Starch, then, of whose weight carbon constitutes nearly one-half, is of course a first-rate combustible. Indeed, one may almost consider it the parent, as it were, of at least half our aliments of combustion, for if (in consequence of a certain operation, which nature has the power of performing for herself, in certain circumstances) it loses a portion of its carbon, so that there remain but 36 ounces of it in the 100 of starch, ou