246 URTICACE^E. 



Constituents. The constituents of American cannabis do not differ 

 from those of Indian caunabis save, perhaps, in degree ; authors pretty 

 generally consider the latter more active than the former. The active 

 properties of cannabis appear to reside chiefly in a resin which has re- 

 ceived the name canndbin ; but there is also found a small proportion of 

 volatile oil possessing the characteristic odor and taste of the plant, and 

 producing narcotic effects. Its remaining constituents are medicinally 

 unimportant. 



Preparations. There are no official preparations of American cannabis. 



FIG. 154. Cannabis sativa. 



It may be employed in the same manner as Indian cannabis, namely, in 

 extract, fluid extract, or tincture. 



Medical Properties and Uses. Cannabis, when fresh, has a peculiar 

 narcotic odor, which is said to be capable of producing headache and 

 other cerebral symptoms. This property is considerably diminished by 

 drying and long keeping, hence the drug should be used as fresh as pos- 

 sible. Indeed, there is little doubt that much of the uncertainty of can- 

 nabis is dependent upon a want of care in this respect. Cannabis is a 

 powerful narcotic, causing, first, exhilaration and delirious hallucinations, 

 generally of a pleasurable character, and afterward drowsiness and stu- 

 por. Though much less certain than opium, it has none of the unpleasant 

 after-effects of the latter, and is often used instead to relieve pain, allay 

 spasm, and produce sleep. 



HUMULUS. HOP. 



Humulus Lupulus Linne. Hop. 



Description. Flowers dioecious. Staminate flowers with 5 sepals, and 

 5 erect stamens. Pistillate flowers with a single sepal, which embraces 



