14 EXPERIMENTAL PHYSIOLOGY 



sulphur called hydrogen sulphide. When animal flesh de- 

 cays it gives off this odor, showing that flesh contains sul- 

 phur.) 



Mention seven properties of sulphur which you have ob- 

 served in the above experiments. 



V. — ^Properties of Carbon. 



Apparatus. — Stick of wood-charcoal, bottle with a small mouth, 

 limewater, ^ glass tube six or eight inches long, beaker, test tubes, 

 splinter of wood, piece of meat, piece of marble, hydrochloric acid. 



Directions. — ^Examine the charcoal stick. (Charcoal is 

 one of the forms of carbon.) What is its color? odor? taste? 

 Does it dissolve in water? 



Light the stick, after trimming it to such a size as to enable 

 it to be thrust through the neck of the bottle. Does it give 

 off any odor in burning? Is it hke or unhke sulphur in this 

 respect? 



Thrust the hghted stick of charcoal into the bottle and 

 keep it there until the flame goes out. Now remove it and 

 cover the mouth of the bottle with the finger. Can you see 

 anything in the bottle? Take a drop of clear lime water 

 in the end of the glass tube and hold it in the air a few 

 minutes. Is there any change in the hme water? Now 

 introduce it into the bottle without touching the sides of 

 the bottle. What happens to the color of the hme water? 

 What sort of substance must be present in the bottle? 

 (When carbon burns it forms a gaseous compound with the 

 oxygen of the air called an oxide of carbon or carbonic acid 



^ Limewater may be made by slaking a little quicklime in water and de- 

 canting the clear liquid. 



