The Birmingham age-herald., 1914-11-08
Atmosphere Surrounds the
 Earth From 50 to 100 Miles in Depth-Fog Ten
 Times Worse Than Smoke

Dr. R. II. Cunningham's twentyfourth health bulletin is devoted to air. It fol- lows:
 The elements forming air are oxygen 21 parts and nitrogen 79 parts. There is no chemical union forming a compound, but they are mechanically mixed in the above proportion forming a gaseous mix ture, each clement retaining it's individual characteristics. The air contains other things, gases. compounds and solids, some of which are normal and others ab- normal. Among those are ozone, car bonic acid gas. watery vapor water, fogs, smoke, dust and bacteria
 Ozone is formed by electrical dis charges, friction between sea waves and the air, oxidation of phosphorescent sub stances, and probably the respiration of plants. It possesses intense oxidizing powers, and is a powerful germicfde, and is found in the air in proportion of one part to one million. It is not found everywhere in the air. being much d. minished in cities and towns, and is not found in inhabited rooms This is due to the large amount of organic matter in these places which exhaust the ozone I in their, oxidation. X larger percentage l of ozone than that mentioned will cause irritation in the respiratory passages and has a distinct odor. Under ordinary conditions, 1t is not injurious to health, but on the contrary may be of benefit by it's oxidizing power.
 Carbonic acid gas (Co2) is found in the air in about three parts per 10000 It is a normal constituent. It is found everywhere in the air. but not in equal proportions. It is formed by combustion, | respiration and by the chemical and biological processes in the soil It is found in greater proportion in cities around manufacturing plants where coal Is burned. There is more near the soil than there is higher up. The natural pro- l portion and even up to 10 parts per 10000 of carbonic acid gas Is not injurious to 1 health. It is not poison, and it's real effects consist in the absence of oxygen in the atmosphere. When an animal dies from carbonic acid gas 1t is not due to the gas, but from the absence of oxygen Another form of carbon and oxygen com | bination is monixide or co. This can take on another molicule of oxygen, and therefore supports combustion. It is I found mostly about charcoal furnaces and other places where coal is not completely oxidized. It is the poisonous element in ordinary lighting gas. (Carbureted hydro l gem Monoxide when breathed unites with the red blood cells in a feeble chemical union and is, therefore. a poison, and not merely mechanical displacement of l oxygen.
 l The atmosphere surrounds the earth, and is said to be from 50 to 100 miles in I depth A square inch column of this atmosphere weighs 15 pounds, and the at mospheric pressure upon the body of an | average man is about 15 tons. which is 1 capitalized by the pressure from within. If this internal pressure were removed man would be instantly crushed; if the outside pressure were suddenly removed,
 he would burst. Atmospheric pressure plays conspicuous part In physical, chemical and biological processes The l air becomes rarer and rarer towards it's top, which must be taken into account
 by those who ascend in the air.
 Temperature
 1 The temperature of the air IS derived i from the sun and earth. It absorbs enor- l nous heat from the suns rays as they l pass through the air, and also from the l earth from which heat escapes by radia- 1 tfon and In evaporation, By the absorp- | ton of the suns rays. there is great miti- | gation of the suns heat in the day time, | and by radiation and evaporation from | the earth at night there is generated warmth in the air. "The atmosphere is | an umbrella at noon and blanket at night" The temperature is highest at l a nd Hff,,fxa afcIa l wards. Atmospheric temperature differs
 in different parts of the world, because
 of physical and geographical differences.
 Movements
 There are certain fixed movements in
 the air known as the trade and anti-trade
 winds When the hot air in the tropics rises it divides into two currents, one going north and the other south towards; the poles. These currents are the anti- trade winds; the cold air from the poles
 returns toward the equator on a lower
 level and are called trade winds. Thes., currents play very important part in the temperature at various points of the earth and take conspicuous part in the formation and transportation of rain.
 Occasional and transient wind currents, even storms occur locally and depend upon the same principles to-wit: differ ence in temperature. The cold denser air rushing into the warm rarer air thus equalizing temperature and density Tha same obtains in rooms and dwellings. the hot air of the inside rises and the cold afr rushes in, and is an important point to be considered in the ventilation of dwellings. Air moving at the rate of
 one mile per hour is imperceptible: two miles an hour it is perceptible or a light breeze; three miles an hour it is a draft:
 90 or 40 and upwards an hour, storms
 and cyclones.
 All movements of the air and their | direction and velocity are caused by differences in temperature at various points.
 Water in the Air
 Water in state of vapor is a nor
 mal constituent of the air. The amount
 of this water measures it shumidity and the amount of vapor is determined by the temperature of the air and its winds. The greater the temperature the greater amount of yapor will tho air contain. Thus cubic foot of air at 10
 degrees F. will hold II grains; at 100 degrees F. cubic foot will hold 100 Erainn. These properties are very | important when the influence of air upon living things is considered. A moigt air will take up less moisture from the body. The body heat is chief ly eliminated and regulated by evap- n Qr:oE fCo