194 THE WONDERFUL HOUSE THAT JACK HAS 



normally remains at a temperature of ninety-eight 

 and six-tenths degrees, without regard to weather, 

 rest, or exercise. Suppose there were a stove that 

 would increase or decrease its heat to remain ninety- 

 eight and six-tenths degrees, regardless of the tem- 

 perature of the room in which it was placed, what 

 a fine invention it would be thought ! 



The pores of our skin are the safety valves in help- 

 ing Jack's House to be just such a stove. We know 

 that insensible perspiration is continually passing 

 from the body. Now when our body's temperature 

 rises above ninety-eight and six-tenths degrees because 

 of heat or exercise, these glands pour out so much ad- 

 ditional perspiration that all the heat not needed to 

 keep up the normal temperature is expended in evapo- 

 rating this water from the skin. How necessary the 

 work of these glands is to our life and comfort, may 

 be judged from the fact that if the skin were covered 

 with any substance that would stop up all the pores, 

 death would soon follow. 



Of what use are the oil glands? They secrete 

 a fluid that lubricates and softens the skin. If oil 

 and the scales that are shed by the skin are allowed 

 to collect on its surface, they form a covering which 

 tends to obstruct the pores and interfere with the 

 proper performance of their work. When such a 

 condition is allowed to continue, the kidneys and lungs 

 are given an abnormal amount of labor in getting rid 

 of the liquid waste of the body. As a natural con- 



