THE LEMON 
Material 
Two lemons for each pupil. (One lemon per pupil will answer, provided 
the pupils work in pairs, the one cutting his lemon horizontally, the other 
vertically and exchanging.) A sharp knife; a piece of paper on which to 
cut the lemon. 
For the study of the oil provide one sheet of white paper per pupil; a 
glass or pan of water (the small glasses mentioned in the material for the 
potato are the best, but common paint pans or saucers can be used); a bottle 
of oil of any kind; an alcohol lamp and a box of matches. If the lamp is 
not obtainable, use a candle, but it is a good plan to let the pupils observe the 
burning of the oil in both the yellow flame of the match and in the colorless 
flame of the alcohol. It is needless to say that these materials should not 
be given out to the class until § 13. [This is a long lesson, but if worked 
through rapidly to a climax will give the young pupils a sense of having 
learned a great deal. The drawings are omitted for this reason, and because 
the orange is essentially the same. ] 
Laboratory Work 
1. Examine the lemon and notice its color and shape. 
Is there any difference in the two ends? 
2. Look at the pointed end or “nose” of the lemon; do 
you find a small brown or black spot on the end 
of it? 
Look at the opposite end ; you will, find one of two 
things, either a little brown or green button, or a 
littlé round hole, the ‘‘ buttonhole.” 
If you find the “ button,” pick it out and then put it 
back, and see how exactly it fits the “ button- 
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