and Laboratory Methods. 2699 



3. Cut off some of the epidermis of a red apple {Afalus tnalus (L.) Britt.), 

 mount, and study the cause of the color. 



4. Mount part of a petal of a red greenhouse Pelargonium. Study the red 

 coloring matter in the cells. 



5. Mount part of a petal of a blue flower (like Salvia pitcher i Torr. or Viola 

 CHCuUata Ait.) and study the nature of the color. 



C. Solution of Aiithocyan. 



1. Take a quantity of the corollas of Maurafidia bardaiana Lindl. (a com- 

 mon greenhouse vine) or flower of Tradescantia virginica L., place them in a dish 

 and after crushing them cover with a quantity of 95 per cent, alcohol. After a 

 day or so pour off the alcohol into a bottle and preserve. 



2. Take a test-tube about one-third full of the alcohol and add a few drops 

 of aqua ammonia. Note color reaction. Neutralize with hydrochloric acid 

 until the liquid is again clear. Continue to add acid drop by drop. What is 

 the color .-* 



3. Place some red pelargonium flowers directly into ammonia water. Note 

 that they change to blue. Transfer to acid alcohol and note that they change 

 back to red. 



4. How do you account for the change of color in many flowers during the 

 period of blooming and for the many varieties of color produced by cultivation 

 as in the common morning-glory {Ipofnaea purpurea (L.) Roth.) ? 



CI. Temperature Test with Aiithocyau. 



1. Take two good thermometers which register alike, wrap the bulb of one 

 in a red begonia leaf and the other in a green begonia leaf, put each in a tum- 

 bler and place for some time in direct sunlight. Note the difference in temper- 

 ature. Place the tumblers with thermometers in diffuse light and note temper- 

 ature again. Place them in a dark box and after a while read the temperature. 

 Make a second test in the sunlight. 



2. Describe one of the uses of anthocyan in roots, stems, leaves, flowers 

 and fruits. 



CI I. Chlorophyll Solution. 



1. Take a quantity of green leaves, such as the blue grass or greenhouse 

 pelargonium ; place them in a porcelain mortar or other suitable dish ; cover 

 with 95 per cent, alcohol ; and crush the leaves thoroughly. After the alcohol 

 is colored a dark green filter into a bottle and keep in a dark place. 



2. Take a small quantity in a test-tube and examine by looking through it 

 toward the window. Note the deep green color produced by the transmitted 

 light. Examine it by reflected light, by standing between the window and the 

 tube, and observe that the color of the solution appears a deep dull red, some- 

 thing like blood. 



3. Take a small quantity of the solution in two test-tubes, and place one in 

 the sunlight and the other in a dark box. How long before the one in the sun- 



