I will only add one trifling detail. 100 ounces of albumen contain as follows:
Ounces.
Carbon 63
Hydrogen —
You can fill up this number yourself, can you not? And knowing the 7 of hydrogen, you may guess what follows! After what we have talked of last time, here is already an explanation of the chicken's growth. But let us go on.
You recollect that yellowish liquid I spoke about, which lies underneath the clot, or coagulum of the blood? I will tell you its name, that we may get on more easily afterward. It is called the serum, a Latin word, which, for once, people have not taken the trouble of translating, and which also means whey. Put this serum on the fire, and in scarcely longer time than it takes to boil an egg hard, it will be full of an opaque white substance, which is the very albumen we are speaking of. Our blood, then, contains white of egg; it contains in fact—if you care to know it—sixty-five times more white of egg than fibrine, for in 1,000 ounces of blood, you will find 195 of albumen, and only three of fibrine; of casein, none.
Nevertheless we eat cheese from time to time. And we generally eat more meat than eggs, and meat is principally composed of fibrine! I should be a good deal puzzled to make you understand this, if we had not our grand list to refer to.
Ounces.
Carbon 63
Hydrogen 7, etc.
Fibrine, casein_, albumen, they are all the same thing in the main. It is one substance assuming different appearances, according to the occasion; like actors who play several parts in a piece, and go behind the scenes from time to time to change their dresses. The usual appearance of the aliment of nutrition in the blood is albumen; and in the stomach, which is the dressing-room of our actors, fibrine and casein disguise themselves ingeniously as albumen; trusting to albumen to come forward afterwards as fibrine or casein, when there is either a muscle to be formed, or milk to be produced.
Know, moreover, that albumen very often comes to us ready dressed, and it is not only from eggs we get it. As we have already found the fibrine of the muscle and the casein of milk in vegetables, so we shall also find there, and that without looking far, the albumen of the egg. It exists in grass, in salad, and in all the soft parts of vegetables. The juice of root-vegetables in particular contains remarkable quantities of it. Boil, for instance, the juice of a turnip, after straining it 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.