178 OUR BODIES AND HOW WE LIVE 



241. The Natural Heat of the Body. Everybody knows 

 that the surface of the body feels warm. Hold the fingers 

 in the mouth and we find it warm. Put a thermometer, 

 made for the purpose, in the mouth and under the tongue 

 for five minutes, and it will register about 98 F., even on 



B 



FIG. 113. Photographs of Two Plates filled with Jelly upon which 

 Molds will readily grow ; showing Abundance of Mold Spores 

 in the Air. 



Plate A was opened to the air for one minute in an ordinary room, and then 

 closed. The room was then swept and plate B exposed to the air for 

 the same length of time. Both plates were then set aside until the 

 spores germinated, when the photographs were made. Plate A shows 

 only one mold, while plate B contains large numbers. Dusting a room 

 produces similar results. 



the coldest day of midwinter. This is the natural heat of 

 a healthy person, and it rarely varies more than a degree 

 or two, except in disease. 



the shoulders, and draw in ten or twelve deep, slow inspirations, holding the 

 breath for three or four seconds each time the lungs are filled. 



These exercises, like breathing in general, should always be done with 

 the mouth closed, for the nose is the only proper channel for the passage 

 to and fro of the air. A school teacher who will interrupt the studies once 

 every hour through the session, and teach the class to do this breathing 

 exercise, will be contributing more than she can ever realize to the future 

 well-being of her pupils. 



