Hygiene, dental and general . In either case an increase in the movement of the air wouldmake it seem colder or cooler because moving air continuallychanges the aerial blanket and increases heat transfer andevaporation. Odors.—We have said that disagreeable odors are injuriousto health in having a definite effect upon the appetite. They VENTILATION, HEATING AND LIGHTING 327 probably also irritate or depress the nervous system. To besure the olfactory nerve soon becomes tired and insensible toa given odor but the depressing effect no doubt continues. The nose can always detect a new odor or a d
Hygiene, dental and general . In either case an increase in the movement of the air wouldmake it seem colder or cooler because moving air continuallychanges the aerial blanket and increases heat transfer andevaporation. Odors.—We have said that disagreeable odors are injuriousto health in having a definite effect upon the appetite. They VENTILATION, HEATING AND LIGHTING 327 probably also irritate or depress the nervous system. To besure the olfactory nerve soon becomes tired and insensible toa given odor but the depressing effect no doubt continues. The nose can always detect a new odor or a different odorand for this reason the odor of the air is a good index of itsfreshness or staleness when one first enters the room. Odorsarise from foul breath, an unclean mouth, decayed teeth, ca-tarrh, the sudoriferous glands from the feet and axillae, andfrom the decomposition of organic matter on the skin andclothes. Moisture is always necessary for the detection ofodors and they therefore become more objectionable as the. Fig. 49.—Wet and dry bulb thermometer for wall attachment. (Courtesy of theTaylor Instrument Companies, Rochester, X. Y.) air becomes more humid. Sometimes heat or a draft of com-pressed air will remove odors from solid surfaces where mereventilation will not. Testing Air.—The air in living rooms which is not beingchanged with sufficient frequency is likely to be odorous andit is not difficult to detect this with the senses upon enteringa close or stuffy room. The test for the amount of carbondioxide in the air will also indicate whether the air is freshor used. The temperature may be read directly from a ther-mometer. 328 HYGIENE: DENTAL AND GENERAL But we must know the relative humidity of air as well asits temperature in order to know whether it is properly con-ditioned for the body. Relative humidity is expressed interms of per cent saturation. When the air is completelysaturated with moisture we have a mist or fog. At 68° optimum humidity
Size: 1111px × 2249px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjecthygiene, bookyear1920
