The History of a Mouthful of Bread by Jean Macé (great novels to read txt) 📕

quite clear, and you will see a white, opaque substance produced, exactly like that which you would observe under similar circumstances in the serum of the blood; real white of egg , that is to say-to call it by the name you are most familiar with-with all its due proportions of carbon, hydrogen, oxygen, and nitrogen.

I wonder whether you feel as I do, dear child; for I own that I turn giddy almost when I look too long into these depths of the mysteries of nature. Here, for instance, is the substance which is found everywhere, and everywhere the same-in the grass as in the egg, in your blood as in turnip-juice! And with this one sole substance which it has pleased the great Creator to throw broadcast into everything you eat, He has fashioned all the thousand portions of your frame, diverse and delicate as they are; never once undoing it, so to speak, to re-arrange differently the elements of which it is composed. From time to time it receives some slight impulse which alters its appearance but not its nature, and that is all. As the chemist found it in the bit of salad, so he will find it again in the tip of your nose, if you will trust him with that for examination. We are proud of our personal appearance sometimes, and smile at ourselves in the looking-glass; we think the body a very precious thing; but yet when we look deeply into it we find it merely so much charcoal, water and air.

This reminds me that we have not yet made acquaintance with the new personage who was lately introduced upon the scene. Nitrogen or
azote , I mean. He plays too important a part to be allowed to remain in obscurity.

You have already learnt that oxygen united with hydrogen produces water. Combined with nitrogen it produces air; but in that case there is no union of the two. They are merely neighbors, occupying between them the whole space extending from the earth's surface to forty or fifty miles above our heads; together everywhere, but everywhere as entire strangers to each other as two Englishmen who have never been introduced! I should be a good deal puzzled to say what nitrogen does in the air: he is there as an inert body, and leaves all the business to the oxygen. When we breathe, for instance, the nitrogen enters our lungs together with its inseparable companion, but it goes out as it went in, without leaving a trace of its passage. Nevertheless, as sometimes happens among men, the one who does nothing takes up the most room. Nitrogen alone occupies four-fifths of the atmosphere, where it is of no other use than to moderate the ardent activity of king oxygen, who would consume everything were he alone. I can compare it to nothing better than to the water you mix with wine, which would be too fiery for your inside if you drank it by itself. This is what nitrogen does. It puts the drag on the car of combustion; as in society, the large proportion of quiet people put the drag on the car of progress (let us for once indulge ourselves in talking like the newspapers!); and such people are of definite use, however irritating their interference may appear in some cases. The world would go on too rapidly if there were nothing but oxygen among men. We have quite enough in having a fifth of it!

But what in the world am I talking about? Let us get back to nitrogen as fast as we can!

We must not imagine there is no energy in this quiet moderator of oxygen. Like those calm people who become terrible when once roused, our nitrogen becomes extremely violent in his actions when he is excited by another substance, and is bent on forming alliances. Sometimes the usually cold neighbor unites itself to oxygen in the closest bonds; in which case the two together form that powerful liquid, aqua-fortis , of which you may have heard, and which corrodes copper, burns the skin, and devours indiscriminately almost everything it comes in contact with. Combined with hydrogen, nitrogen forms ammonia , which is still often called by its old name volatile alkali ; one of the most powerful bodies in existence, and one for which you would very soon learn to entertain a proper respect, if somebody were to uncork a bottle of it under your nose. Finally, nitrogen and carbon combined, produce a quite foreign substance ( cyanogen ), resembling neither father nor mother in its actions and powers, to the confusion of all preconceived ideas, when Gay-Lussac, a Frenchman, introduced it to the world, where it fell like a bombshell upon the theory of chemical combinations. This impertinent fellow, combining with hydrogen in his turn, produces prussic acid , the most frightful of poisons; one drop of which placed on the tongue of a horse strikes it dead as if by lightning.

You perceive that you must not trust our worthy friend too far. You have learnt, however, elsewhere, that it is not equally formidable in all its combinations. Those very substances which, when paired off into small separate groups, destroy all before them, constitute, all four together, that precious aliment of nutrition of which we are formed. Moreover, its real name is " azotized aliment " because it is the presence of nitrogen or azote in it, which, above all, determines its quality, so that people are in the habit of estimating the nourishing power of our food by the amount of nitrogen it contains. In fact, nitrogen seems to be a substance especially inclined towards everything that has life. His three comrades wander in mighty streams, so to speak, through every part of creation; but he, except in the vast domain of the atmosphere, where he reigns in such majestic repose, is rarely met with, except in animals, or in such portions of plants as are destined for the support of animal life.

On this point I will tell you the history of his original name,
azote , which you will find curious enough. A short time before the French Revolution, in 1789, the principal properties of this gas were made known to the world by a learned Frenchman, who may be almost considered the father of modern chemistry, and whose name I must beg you to recollect. [Footnote: Dr. Daniel Rutherford (Edinburgh) discovered the existence of Nitrogen , A. D. 1772; but he never investigated its character.] He was called Lavoisier . While endeavoring to account satisfactorily for combustion , which before his time people explained any way they could, Lavoisier succeeded in separating our two friends, the neighbors in the atmosphere, one from the other, and was the first man in the world who managed to secure in two bottles-on the one hand, the bubbling oxygen freed from his tiresome mentor; on the other, the sober *azote, snatched away from his giddy pupil. What he did with the bottle of oxygen matters but little to us; but in the bottle of azote he plunged, by way of experiment, an unfortunate mouse, and subsequently a little bird, both of whom, finding no oxygen to breathe, died one after the other. Nothing could live in it, as you may suppose; and Lavoisier thought it must be right to give so destructive a gas the name of azote , which in Greek means " opposed to life ." Meantime, science went on progressing by the gleam of the lamp he had lit, and then followed the discoveries of his successors, who forced their way into the obscure laboratory where the elements of living bodies are prepared. And at last it was ascertained that this azote , opposed to life as it was thought to be, was actually an essential property of life; that it accompanied it everywhere, and that without it the whole framework of the animal machine would fall to pieces. It is still known by its old name, which custom had sanctioned; but I imagine no learned man can ever utter it now without a feeling of humility, and without the thought that the future has possibly many contradictions in store for him also. Besides, nitrogen has to pass through many fine-drawing processes before it attains that post of honor which has been assigned to it in the animal kingdom. The animal himself can do nothing with it, unless it has been previously absorbed and digested by the vegetable, and the vegetable in its turn could get no good from it, were it to remain isolated and indifferent in the bosom of the atmosphere. It is only when it has formed one of those combinations I have been telling you about, and more particularly the second, which produces ammonia , that it fairly enters upon the round of life. And then, in the mysterious depths of vegetable existence is organized that wonderful quadrille of the aliments of nutrition , the history of which has now been sufficiently explained to you.

The vegetable kingdom, therefore, is simply the great kitchen in which the dinner of the animal kingdom is being constantly made ready; and when we eat beef, it is, in fact, the grass which the ox has eaten, which nourishes us. The animal is only a medium which transmits intact to us the albumen extracted in his own stomach from the juices furnished to him in the fields. He is the waiter of the eating-house; the dishes which he brings us have been given him already cooked in the kitchen. But to appreciate properly the service he renders us we must remember that the dishes to be obtained from grass are very, very small, and that it would be a great fatigue to the stomach if it could only get at such tiny scraps at a time; as, alas! has sometimes happened to the famine-stricken poor, who have tried in vain to support life from the grass in the field. But these minute dishes are brought to us in the mass whenever we eat beef, and our stomachs benefit accordingly. Do not forget this, my child; and when mamma asks you to eat meat, obey her with a good grace; if, that is to say, you wish to grow up to be a woman.


LETTER XXVIII.

COMPOSITION OF THE BLOOD.

One word more before we finish. We must not leave off without bidding a last farewell to the good servant of whom we have spoken so much; the model steward so exact in giving back everything he receives-the factotum of the house in short. We have watched him at work long enough, but I have not yet described him personally to you, nor told you exactly what he is composed of.

And here I shall be obliged to begin again with figures and calculations, although I am told young people are not very fond of them. Nevertheless, none of us can manage our affairs properly without them. Hereafter, when you are at the head of a family, you will be obliged to practise arithmetic, if you want to know what is going on in your house. Never allow yourself to look upon what is necessary as wearisome; the true secret of being punctual in our duties is to throw our heart and interest into them.

I choose, therefore, to suppose that you will be interested to know that 1000 ounces of blood generally contain, (for there are shades of difference between one sort of blood and another) 870 ounces of the
serum I have been talking about, and 130 ounces of clot . At first sight one would take