Oxygen mask

“ Other types which have proven more effective are designed after the fashion of the diving apparatus, and having a small tank of compressed oxygen with feeding tubes running to the mask. The oxygen combines with the contaminated air breathed through absorbent cotton or sponge and provides the wearer with the proportion of oxygen necessary to existence. ”

“ Freezing of moist oxygen at extremely low temperature. Obstruction of openings in regulator. Hole in rubber diaphragm in regulator. Breathing too deeply may produce a partial vacuum inside mask causing air to leak in from bottom or sides. BREATHE NATURALLY. Don't expect to get oxygen from an empty walk-around bottle. If not fully charged, the bottle may last only a minute or two. Improper use of walk-around equipment. OXYGEN DISCIPLINE
It is mandatory that every member of a heavy combat crew be highly trained in oxygen discipline. ”

“ The first of these, the so-called “economiser” pattern, by means of an arrangement of valves, allowed oxygen flowing from the apparatus to mix with the air on inhalation, but stored it up and thus prevented waste on exhalation of the breath. It was found that, owing to the resistance imposed by these valves upon breathing, the mask could not be used, the strain thrown upon the lungs being too great. ”

“ Only older ships will be equipped with the bouncing ball which is no longer manufactured. These indicators do not tell HOW MUCH oxygen you are getting ... they merely indicate that some oxygen is flowing through the system when you take a breath. They may be working O.K. even though your oxygen supply is inadequate. The COLOR OF YOUR FINGER NAILS is a better guide to the amount of oxygen you are getting, providing your hands are warm. If they become bluish above 20,000 feet check mask and connections for leak. ”

“ All these fire extinguishers were checked and recertified during 1987.
1.14.5 Supplemental oxygen is provided by separate fixed systems for the flight crew and passengers, and portable oxygen bottles are positioned throughout the cabln and cockpit for use if needed. Individual oxygen masks are automatically released from the passenger service units when the cabin altitude is at or above 14 000 feet. The B-747 Operations Manual warns that passenger oxygen use should be discontinued "below 14 000 feet when smoke or an abnormal heat source is present. ”

“ Even short-term inhalation of harmful substances at sufficiently high concentrations can cause death or permanent damage to health, and effects on the eyes can prevent to leave the dangerous place. When gas cartridges are replaced in a timely manner, this may happen when there are gaps between the mask and the face. Then one inhaled the air, the pressure under the mask became below atmospheric pressure. Studies have been conducted to measure the protective properties of respirators in the laboratory and in the workplace. ”

“ Now, what I wish to have you understand by that, is this: that the average man requires about 137,200 cubic inches of oxygen in every twenty-four hours. This is the accepted way of putting it; in reality, he needs the ozone contained in that amount of oxygen. I do not desire that you should receive the impression that the oxygen is not needed for the man, but that the ozone only is required for the continuance of life where there is no action. I may surprise you when I say that each of you draws into your lungs, every day, over seven pounds of oxygen gas, but such is the case. ”

“ 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 poisonous action of carbon monoxide can be abolished by placing the animal exposed to it in oxygen at an excess pressure of about an atmosphere. The reason for this is that, in consequence of the increased partial pressure of the oxygen, the amount of this gas in free solution in the blood is greatly increased in accordance with Dalton's law, and becomes sufficient to supply the tissues with oxygen quite independently of the haemoglobin. Even at ordinary atmospheric' pressure the extra oxygen dissolved in the blood when pure oxygen is breathed is of considerable importance. ”

“ Now it has all burnt out—what a pity!" "Now, Rudolph, I want to tell you about it. You must know that the air we breathe is made up of this oxygen, of nitrogen, a [Pg 46] very little carbonic acid gas, and a small quantity of water. If the oxygen was taken out of the air, you could not live for one moment: I'll show you. You see this jar? It is full of nitrogen—of air with the oxygen taken out." "But what are you putting into it? A little mouse, I declare!" "Yes: but you see it dies instantly; it cannot live because there is no oxygen in the air." ”

“ Nitrous oxide gas is composed of the same elements as ordinary air, with a larger equivalent of oxygen, except it is a chemical compound, not a mechanical mixture, and its anaesthetic effects are said to be due to the excess of oxygen. If this be a fact, then why can you not produce a similar effect by rapid breathing for a minute, more or less, by which a larger quantity of oxygen is presented in the lungs for absorption by the blood? ”

“ As the oxygen is removed in the passage of the blood through the body, there results in venous blood reduced hemoglobin, which is of a purplish color. Upon exposure to the air, however, it absorbs oxygen once more and resumes its scarlet color. If carbon monoxide gets into the blood, as in cases of gas poisoning, it drives off the oxygen and forms a more stable compound with the hemoglobin, whence the difficulty in restoring a person so poisoned. ”

“ It is a powerful supporter of combustion, and is absolutely necessary for the support of animal life, which cannot exist for any time without a free supply of this gas, which is constantly consumed in the act of breathing and is replaced by an equivalent portion of carbonic acid gas. The want of oxygen is partly the cause of the oppression felt in crowded rooms, where the air cannot be renewed so fast as is required for the number of persons who are constantly consuming the oxygen ”

“ Canaries and white mice are used in large numbers to detect the presence of poisonous gases below, and, being very susceptible to bad air, are soon killed. [It is a curious sight to see these canaries hung up outside dugouts in all trenches where mining operations are conducted.] Both Doherty and I had previously been trained in the use of the oxygen apparatus, and were quite confident of its ability to take care of the carbon monoxide so that it would not affect our lungs. ”

“ Experimental evidence is strongly in favor of my argument that the chemical purity of the air is of no importance. Analyses show that the oxygen in the worst-ventilated school-room, chapel or theater is never lessened by more than 1 per cent, of an atmosphere; the ventilation through chink and cranny, chimney, door and window, and the porous brick wall, suffices to prevent a greater diminution. So long as there is present a partial pressure of oxygen sufficient to change the hemoglobin of the venous blood into oxyhemoglobin there can arise no lack of oxygen. ”

“ When it is held in combination with oxygen or common air, it acts much like oxygen, but more powerfully. It affects the pulse, the respiration, and the circulation, in various ways, according to the quantity taken, and the temperament of the individual. In this respect, it behaves like electricity. It has been thought that ozone is formed in the body from the contact of oxygen gas with the blood, and there are those who believe that it is absorbed with the ozone in the air, and is carried into the blood, where it takes part in the process of oxidation. ”

“ An animal which breathes pure oxygen, becomes flushed, pants violently, and, if not choked, dies of inflammation of the lungs, produced by the intense action. In the air we breathe, the oxygen gas is diluted to the proper degree by another gas, termed nitrogen, which is totally destitute of power; it does of itself no good and no harm; it is the only substance that could be mixed in the air we breathe, without interfering in any way. When thus the blood loses, by exposure to the air in the lungs, its carbonic acid, it takes oxygen in its place ”

“ It will be dark in three-quarters of an hour and I hope that everyone will stay under cover as much as possible."
Davis looked up as Dr. Bird entered the laboratory.
"I'll have the masks completed in an hour, Doctor," he said, "but I don't know how much value they will be. If the oxygen polymerizes before it enters the body, these masks ought to stop it, but if it polymerizes under the influence of heat and moisture in the lungs, they will be useless."
"I'll have to take a chance on that, Davis. From the description of the fog, I strongly suspect that the process takes place outside the body. ”

“ 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. ”

“ Later it was realized that this slow combustion did not take place in the lungs, or in the blood, but in the [Pg 92] tissues cells themselves and respiration in the chemical sense has come to mean this universal slow combustion in the cells of the body rather than the breathing movements of the lungs themselves. In anaerobic respiration, CO2 is given off, but no oxygen absorbed. In aerobic respiration, oxygen is absorbed and CO2 given off. In addition we know of many substances which oxidize by taking up oxygen without giving off CO2. ”

“ Currie, the effects of which are wonderful, but which can only be applied at the commencement of the disease. In all diseases of indirect debility, therefore, it is proper to attempt the introduction of oxygen into the system, by the oxygenated muriate of potash, acid fruits, nitre, &c. I do not think that the inhaling of oxygen gas for a few minutes in the day can do much good; but free ventilation of apartments, and gentle exercise in the open air, are highly useful. ”

“ If there was such an immense quantity of oxygen, how fearfully fast everything would burn! Our bodies would soon rise above fever heat from the quantity of oxygen we should take in, and all fires and lights would burn furiously. In fact, a flame once lighted would spread so rapidly that no power on earth could stop it, and everything would be destroyed. So the lazy nitrogen is very useful in keeping the oxygen-atoms apart; and we have time, even when a fire is very large and powerful, to put it out before it has drawn in more and more oxygen from the surrounding air. ”

“ Later, too, I learned that the membrane-like frills upon these creatures are a sort of gills, or as I might say, natural gas-masks, which by some means enable the beings to breathe the sulphur-laden air. But even with these, they avoid the lower areas where the fumes are the worst, and only visit them when necessity arises, which accounts for my being left in peace, with none of the horrible women near the ship, for days at a time. I discovered the presence of the sulphur gas on the first day when, attempting to eat, I removed my gas-mask. ”

“ When the air is received into the lungs, the oxygen is extracted from it, eaten up, as it were, and distributed through the system; and, on the exhalation, the carbonic gas and organic matter is carried out. If a person is confined within a limited space, and little air permitted to enter, he will soon consume most of the oxygen contained therein, poison the atmosphere with the carbonic gas which he throws off, [p. 123] and die for the want of the life-giving property—oxygen. It is estimated that almost half the deaths are caused through improper breathing and the inhalation of vitiated air. ”

“ Impurities of the Air.—The oxygen in the atmosphere is of such prime importance, and its proportion is so nicely adjusted to the wants of man, that any gas or volatile substance which supplants it must be regarded as a hurtful impurity. All gases, however, are not alike injurious. Some, if inhaled, are necessarily fatal; arsenuretted hydrogen being one of these, a single bubble of which destroyed the life of its discoverer, Gehlen. Others are not directly dangerous, but by taking the place of oxygen, and excluding it from the lungs, they become so. ”

“ But if oxygen, in the form of gas, can be forced through water, it will attack the germs, and destroy them.
Common Air Not a Good Purifier.—Water may be purified, to a certain extent, by forcing common air through it, and the foulest water, if run over rocks, will be purified, in a measure, because air is intermingled with it. But common air is composed of four-fifths nitrogen, and only one-fifth oxygen, and, as nitrogen is the staple article of food for bacteria, the purifying method by air is not effectual. ”