Il6 PASTORAL AND AGRICULTURAL BOTANY 



a. Test the action of the leaves of Jimson weed, especially if fresh, by rubbing the 

 leaves with the index finger and then rubbing the eye balls with the finger. Does the 

 pupil dilate as a result of such treatment? 



3. The following test with hyoscyamin can be made. Hyoscyamin shows an alka- 

 line reaction with phenolptalein and causes a yellow to red precipitate_when touched 

 with a 2 per cent/solution of mercuric chloride in diluted alcohol. 



4. Examine microscopically and draw the pollen of the ragweeds, Ambrosia artemisi- 

 aefolia and Ambrosia trifida, preserved in weak formalin (2 per cent.) for this purpose, 

 or dried pollen may be substituted, when mounted in water for examination. 



