70 APPENDIX I. 
EXPERIMENT 5. CARBOHYDRATES (Sugar and Starch). 
(a) To test for. 
If weak iodine is added to starch, especially in solution, a 
bluish color will result. In testing seeds and roots, crush, boil 
in water, and cool before applying the iodine. Green plant 
parts must have been in the sunlight for some time, and it is 
best to remove the chlorophyl before the test is made. 
Fehling’s solution added to grape sugar and boiled will give 
a brick-red color. It is usually desirable to crush the seeds, 
or other hard parts, before testing. 
(b) To show the necessity of. 
To a fungus. 
Place yeast in water without sugar or other food. In 
another vessel place yeast with water and a little sugar. 
Which shows growth with an evolution of a gas? Why? 
To an alga in the dark. 
Place an actively growing alga in a weak grape sugar solu- 
tion, and another quantity of alga in distilled water. Keep 
both in a dark place. After several days one dies, and the 
other is still active. Explain results. 
EXPERIMENT 6. HYDROCARBONS (Oils). 
To test for. 
Crush seeds, or other parts to be tested, and place in a bottle 
with ether; cork and allow to stand for some time. Then 
decant the liquid, and permit the ether to evaporate. If oil is 
present, it will easily be seen. ’ 
EXPERIMENT 7. PROTEIDS (Nitrogenous Substances). 
(a) To test for. 
Crush the substance to be tested. Add Millon’s solution and 
boil. If a proteid is present, it will be denoted by a pink or 
reddish color or coagulum appearing in the solution. 
