10 LABORATORY LESSONS IN GENERAL SCIENCE 



The rusting of iron and the decay of vegetation are il- 

 lustrations of oxidation. Why are these not commonly con- 

 sidered cases of combustion ? 



3. Into an evaporating dish put a teaspoonful of gasoline. 

 Bring to it a lighted splinter, and observe. 



Half fill another dish with kerosene, and test in like man- 

 ner. Pour out all but a little of the kerosene and warm 

 slowly what is left, testing frequently with a lighted splinter 

 held just above the dish. What is the nature of flame f 



4. Light a candle. After a moment extinguish it, and 

 immediately hold a lighted match just above the wick. 

 Repeat several times, noting whether the wick can be ig- 

 nited when the flame is some distance from it. How is this 

 possible? What is the "flame" of a candle? What con- 

 ditions are necessary for any flame? Name in order the 

 steps in the ignition and continued combustion of a candle. 



5. Note the parts of a candle flame distinguished by color, 

 and state their relation to the wick and to one another. Hold 



in the candle flame just above the wick the 

 wood part of a match, withdrawing it after 

 a moment to observe the positions of the 

 charred parts with reference to the parts of 

 the flame. Repeat several times, and infer 

 concerning the interior of the flame. 

 FIG. 6. Parts of Press down over the candle flame nearly 



a candle flame. 



to the wick a sheet of white paper. With- 

 draw it before the paper ignites, and observe the form of 

 the charred portion. From several such attempts reach a 

 conclusion as to the interior of the flame. 



Describe the parts of a candle flame as to nature and form. 



