CANNABIS 153 



gathered while the fruits are yet undeveloped and are carrying all 

 their natural resin. Haschish, bhang, charas, ganga, etc., are dif- 

 ferent preparations of the drug used by the natives of the East as 

 habit drugs. The United States Pharmacopoeia requires a physio- 

 logical assay of preparations of cannabis. 



Constituents. Cannabis contains 29 per cent, of resin, a vola- 

 tile oil, and very minute amounts of an alkaloid cannabinine and 

 some other alkaloids. Its activity is due to the resin. Cannibinol 

 is a mixture consisting chiefly of resin and oil. Cannabis is very 

 variable in strength unless standardized, and furthermore, tends to 

 deteriorate. It was formerly supposed that the Indian plant was a 

 distinct species but it differs so little from other forms that botanists 

 now agree that it is merely a different variety. It was also thought 

 to contain no medical properties when grown in temperate climates 

 and that only the Indian variety was of therapeutic value. Experi- 

 ments, however, have shown that other varieties are valuable, espe- 

 cially Cannabis Africana and Cannabis Americana. The fluid-ex- 

 tract of either is now standardized by the best pharmaceutical houses 

 so that the dose is the same as that of the Indian drug. Water pre- 

 cipitates the resin. 



Preparations and Doses. 



Extractum Cannabis. H. 3ss — ij ; 2. — 8. D. gr. -^4 — ij ; 



0.015—0.12. 



Fluidextractum Cannabis. H. 3iv — ^viij ; 16. — 30. D. Tl\_ 



i — x; 0.06—0.6. 



Tinctura Cannabis. H. Not used. D. tT|, xv — xxx; 



1.-2. 



External and Local Action. There is no action on the un- 

 broken skin but it may be slightly sedative to mucous membranes. 



Digestive Tract. Cannabis has no direct effect upon the di- 

 gestive tract. Its use is not followed by constipation or other bad 

 effects. 



Nervous System. Cannabis is a distinct depressant to the brain 

 and cord. In man this action may be preceded by a brief period 

 of stimulation but this action is rarely seen in the horse. It is a 

 distinct depressant and hypnotic and probably ranks ahead of opium 

 for this purpose in equine practice. After full doses the animals 

 feel drowsy, sleepy, have a disinclination to move and may finally 

 pass into a stage of narcosis which may last from 12 to 24 hours, 

 and then recover. There is some diiference in the action of can- 

 nabis on different animals and occasionally there is an idiosyncrasy 

 toward the drug. Some dogs show deliriiun and mania instead of 

 depression. 



Respiratory and Circulatory Systems. These are but little 

 influenced although there may be some acceleration of the pulse 



