First Lessons in Physiology for Elementary Classes

First Lessons in Physiology for Elementary Classes

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1899 edition. Excerpt: ... what it needs. 19. VEN'J.'ILATIoN.--We have learned why the air of our sleeping-rooms, schoolrooms, and public buildings is often impure. Now let us inquire how we can keep the air pure in our rooms without danger of our taking cold. n the summer this is an easy matter, as the doors and 'windows are almost always open. When our windows are of the common sash kind (Fig. 38), a good supply of fresh air may be obtained without a draught by placing a board about four inches wide under the lower sash. The window is thus closed against rain and snow, but allows a supply of fresh air to enter between the sashes. If we open the windows or doors at opposite sides of the room, the bad air will be carried ofi, and pure air will take its 'place. If we have but one window in 'the room, it is a good plan to open it 'l 1 _ at the top as well as i at the bottom, a little "1, way even in very I '; cold weather. The 'l bad air, so long as it is warm, is lighter, than the pure air i and rises to the top of the room. For Fm. 38.--Showing manner of ventilating by in-'-serting strip of wood beneath lower sash of this reason It will go window. out at the top of the window, while the pure air, being heavier, comes in at the bottom. 20. BED-RooM VaNT1mTioN.-We need not be afraid of too much fresh air in our sleeping-rooms. Even in cold weather we can have clothing enough on our beds to keep us warm; and cold air in our rooms, if it is fresh, is better than bad air. Night air, that so many people are afraid of, will not hurt us. We all know that we sleep better, when the air is pure at night, and awake feeling rested and ready for work again. On the other hand, if we shut out the pure air, we awake feeling tired, and are...
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Product details

  • Paperback | 38 pages
  • 189 x 246 x 2mm | 86g
  • United States
  • English
  • black & white illustrations
  • 1236841085
  • 9781236841087