Oxygen

“ We take in oxygen with the air, and the oxygen unites with carbon, and makes carbonic acid, and with hydrogen, forms water.”
“Then don't the hydrogen and carbon combine with the oxygen—that is, burn—in the lungs, and isn't the chest the fire-place, after all?” asked Mr. Bagges.
“Not altogether, according to those who are supposed to know better. They are of opinion, that some of the oxygen unites with the carbon and hydrogen of the blood in the lungs: but that most of it is merely absorbed by the blood, and dissolved in it in the first instance.” ”

“ The oxygen taken into the lungs is not used there, but is carried by the blood to such parts of the body as need oxygen to oxidize food materials in the cells. Since work is done in the cells of the body, food and oxygen are therefore required. The quantity of oxygen used by the body is nearly dependent on the amount of work performed. Oxygen is constantly taken from the blood by tissues in a state of rest and is used up when the body is at work. This is suggested by the fact that in a given time a man, when working, gives off more oxygen (in carbon dioxide) than he takes in during that time. ”

“ Oxygen and the Maintenance of Life.—In the supplying of energy to the body, one of the conditions necessary to the maintenance of life is provided. Because oxygen is necessary to this process, and because death quickly results when the supply of it is cut off, oxygen is frequently called the supporter of life. This idea is misleading, for oxygen has no more to do with the maintenance of life than have the food materials with which it unites. Life appears to be more dependent upon oxygen than upon food, simply because the supply of it in the body at any time is exceedingly small. ”

“ The oxygen of the air when it enters the lungs is diluted with four volumes of nitrogen, which is not absorbed into the system, so that the blood absorbs but a small quantity of oxygen from the air, whilst in an atmosphere of pure oxygen a large quantity of oxygen would be absorbed, and would produce a very rapid change of all parts of the organism, and destroy it. ”

“ Thus, oxygen compounds predominate on the earth's surface. Besides this, a portion exists in a free state, and is contained in admixture with nitrogen in the atmosphere, forming about one-fourth of its mass, or one-fifth of its volume.
Being so widely distributed in nature, oxygen plays a very important part in it, for a number of the phenomena which take place before us are mainly dependent on it. Animals breathe air in order to obtain only oxygen from it, the oxygen entering into their respiratory organs (the lungs of human beings and animals, the gills of fishes, and the trachæ of insects) ”

“ Why the Red Cells Carry only Oxygen to the Body. But why do not the red cells carry air instead of just oxygen? This is simply a clever little economy of space on nature's part. As a chemist will tell you the air which we breathe is a mixture of two gases—one called nitrogen and the other oxygen; just as syrup, for instance, is a mixture of sugar and water. Then too, as in syrup, there are different amounts of the two substances in the mixture: as syrup is made up of about one-quarter sugar and three-quarters water, so air is made up of one-fifth oxygen and four-fifths nitrogen. ”

“ It must be remembered that the oxygen contained in the air of the room would be constantly undergoing reduction by respiration during the night. If the quantity thus consumed were determined from the quantity of carbonic acid exhaled, allowing for the fact that 15 per cent. more oxygen is taken into the blood than is contained in the carbonic acid of the air expired, it will be found that from one-third to one-half of the oxygen originally contained in the air of the room would have been consumed by the end of the night. ”

“ It is these oxygen-atoms which we use up when we breathe. If I had put a mouse under the bell-jar, instead of the phosphorus, the water would have risen just the same, because the mouse would have breathed in the oxygen and used it up in its body, joining it to carbon and making a bad gas, carbonic acid, which would also melt in the water, and when all the oxygen was used, the mouse would have died. ”

“ You must know, then, that air is composed of two gases,—oxygen and nitrogen; therefore, when we breathe, we send into our lungs oxygen and nitrogen. You might think, when we throw out this air, when we exhale,—you might think, I say, that this air coming out of our lungs is still composed of oxygen and of nitrogen in the same proportions. Now, it is not so at all. The quantity of nitrogen has not varied, but, in the first place, there is less oxygen, and there is another gas,—carbonic acid gas ”

“ So far as is known, the intake'of oxygen, either free or combined, and the output of carbon dioxide, are an essential part of the life of all organisms. The two processes are so closely associated with one another that they are always included together under the designation of respiration, which may thus be defined as the physiological process which is concerned in the intake of oxygen and output of carbon dioxide. According to the evidence at present available, it is only within living cells that the respiratory oxygen is consumed and the carbon dioxide formed. ”

“ Not only is oxygen the most active of chemical elements, if both intensity and variety of chemical behavior be considered, and far the commonest upon the earth's surface, but also the most important chemical processes are reactions of oxygen. ”

“ Indeed, it seems quite probable that the oxygen in our own air is not destined for ever to remain there. It passes through various vicissitudes by being absorbed by animals and then restored again in a free state under the influence of vegetation. But there is an appetite for oxygen among the inorganic materials of our globe which seems capable of using up all the oxygen on the globe and still remaining unsatiated. ”

“ Let us inquire, then, into the value of the slight increase of oxygen.
There is a wide-spread opinion that the breathing of air rich in oxygen effects a more rapid transformation of matter, a more rapid combustion, as we say, in the body. Even great inquirers and thinkers have considered that we only eat and imbibe nourishment to satiate the oxygen streaming through us, which would otherwise consume us. ”

“ Our Use of Oxygen.—We are breathing out carbonic acid gas; and on breathing through a piece of glass tubing into some of the clear lime-water we shall see that it will be turned milky in just the same way as when the candle burned. We are using up oxygen to support life, the candle uses up oxygen to support life, and in both cases the product is carbonic acid gas, as we have proved by means of the lime-water test. (See Fig. 7.) ”

“ The oxygen is, of course, chiefly supplied from the air, and, to a less degree, from water. Hence the necessity of good respiratory apparatus,—lungs that shall not only work well, but shall have as great volume as possible. The oxygen is rapidly consumed In the body. The greater the amount of exercise, the greater the waste, or rather expenditure, of material, including oxygen, and the greater the necessity for having large reservoirs from which to draw. ”

“ Thus a fire burns the faster the more air is supplied, and the higher the percentage of oxygen in the air. It was for long believed that in the living body also the rate of oxidation must vary according to the oxygen supply. It has been found, however, that this is not the case. Provided that a certain minimum of oxygen is present in the air breathed, or in the blood supplied to the tissues, it is, practically speaking, indifferent whether the oxygen supply be increased or diminished: only a certain amount is consumed. ”

“ The more fresh air, i.e., the more oxygen we get into our lungs, the more we can contribute to the processes of oxidation in the tissues. When the processes of circulation and of breathing are checked, and when insufficient oxygen is absorbed, we soon see a very important change for the worse in the condition of such persons, as exemplified by cases of heart and lung trouble.
Given the great importance of oxygen, we must try by every means to get as much of it into our lungs as possible; we shall get more of it from air that is not stagnating, but always in circulation. ”

“ Inasmuch as this oxygen is very pure and much less expensive than the chemically-prepared oxygen, extensive provisions have been made for its continued use. Instead of using small cylinders containing 10 cubic feet and attaching thereto purifying devices in the shape of soda-lime U-tubes and a sulphuric-acid drying-tube, we now use large cylinders and we have found that the oxygen from liquid air is practically free from carbon dioxide and water-vapor, the quantities present being wholly negligible in experiments such as these. ”

“ We have learned also that oxygen, taken up in the air cells of the lungs, is being continually carried to the tissues, and that the blood is purified by being deprived in the lungs of its excess of carbon dioxid. From this tissue activity, which is mainly oxidation, are formed certain waste products which, as we have seen, are absorbed by the capillaries and lymphatics and carried into the venous circulation. ”

“ Oxygen has its Limitations.—​We know all about it; what we forget, perhaps, is, that even oxygen has its limitation: nothing can act but where it is, and, waste attends work, hold true for this vital gas as for other matters. Fire and lamp and breathing beings are all consumers of the oxygen which sustains them. What follows? Why, that this element, which is present in the ratio of twenty-three parts to the hundred in pure air, is subject to an enormous drain [Pg 31] within the four walls of a house, where the air is more or less stationary. ”

“ In this state the oxygen is transpired by the leaves of plants when exposed to the sun’s rays. Thus you find that the decomposition of water, by the organs of the plant, is not only a means of supplying it with its chief ingredient, hydrogen, but at the same time of replenishing the atmosphere with oxygen, a principle which requires continual renovation, to make up for the great consumption of it occasioned by the numerous oxygenations, combustions, and respirations, that are constantly taking place on the surface of the globe. ”

“ We should expect oxygen to be present in the body fluids, because it is necessary for the metabolism of cells and can get to them only by being carried in the blood stream. We have seen in the red corpuscles the special method by which an abundance of oxygen is transported. Carbon dioxide is the gaseous product of the oxidation of carbon and is found in large amounts wherever there is burning, since carbon is the chief constituent of all fuel and whenever carbon is burned, carbon dioxide is formed. ”

“ Those crystals are pure oxygen."
"Impossible! Oxygen is a gas at all ordinary temperatures."
"Yes, a gas, but one whose density varies. Oxygen, to which we chemists assign the formula O2, meaning that its molecule consists of two atoms of oxygen, has a weight of 32 grams per gram molecule. Ozone, to which we assign the formula O3, meaning that its molecule contains three atoms of oxygen, weighs fifty per cent more or 48 grams per gram molecule. This new form has a density less than water, but tremendously greater than any known gas. ”