PRACTICAL WORK QI 



(2) With solution of zinc chloride in potassium iodide 



(" Schulze's solution ") proteins turn yellow as before, 

 starch blue, cellulose blue or purple, fats remain 

 uncoloured. 



(3) With Sudan 3 (an anilin dye) proteins, starch and fats 



remain uncoloured, fats turn orange-red. 



Stain an example of each of the three sections of different 

 seeds : (a) bean, (p) castor oil plant (Ricinus), (c) lupin, in watch- 

 glasses containing the reagents (i), (2), (3) above. Wash in 

 water and mount in dilute glycerine. Draw a single suitable 

 cell of each section under the high power, and determine the 

 classes of food substance present in each. 



