254 APPLIED PHYSIOLOGY 



4. When, in Bright's disease, or from any other cause, 



the kidneys cease acting, death by poisoning soon 

 takes place. 



5. The skin can aid the kidneys, but cannot take their 



place. 



6. Alcohol causes poisons to develop whose excretion 



overworks the kidneys. 



7. The liver and intestine each excrete a great amount 



of waste and poisonous substances. 



8. The excretions from man remain poisonous until 



destroyed by the soil, by plants, or by running 

 water. 



9. In thickly settled districts it is necessary to carry off 



the excretions by means of a sewer. 



DEMONSTRATIONS 



106. Carefully weigh several boys early on a warm day. Have 

 them run about and take violent exercise, eating and drinking nothing, 

 or only known amounts. In a few hours weigh them again. A loss of 

 half a pound or more may be noted. 



107. Insensible perspiration may be shown by touching a cold glass 

 to the skin, when moisture will at once condense upon the glass. 



108. Secure a specimen of kidney mounted for the microscope. 

 With a power of about 200 diameters show the class how capillaries 

 form a bunch in a pocket at the beginning of each tube, and then pass 

 out to surround the tubes, and finally unite to form the veins. Show 

 them the large size of the cells of the tube. 



109. Cut open a pig's or sheep's kidney lengthwise and notice the 

 pocket in its side and the radiating lines of the kidney reaching almost 

 to the surface and marking the course of the tubes. 



no. A pot of growing flowers will illustrate nature's method of dis- 

 posing of sewage. Although manure and dirty water are poured upon 

 the earth, yet they give out no odor, but become fresh and clean and 

 nourish the plant. 



III. Show the pupils the traps for sewer gas under the sinks. 



