1182 INDIAN MEDICINAL PLANTS 



from '925 to "931 ; saponification value, 190 to 193 ; iodine value, 144 to 166; 

 the fatty acids melt at 17° to 19°. It is used on the Continent as a paint oil 

 and for making soft soap. (Hooper.) 



The essential oil purified by distillation in a current of steam and extrac- 

 tion with ether, is a mobile liquid boiling at 248-268° ; after repeated distillation 

 from metallic sodium in order to remove as tearoptene, it yields a sesquiter- 

 pene C 1S H 24 , as a mobile, colourless oil of aromatic odour, which boils at 

 256°, and has a density of 0'897 at 15*3°, and is slightly Isevorotatory. This 

 soon resinifies on exposure to air, and on adding concentrated sulphuric acid 

 to its chloroform solution, the liquid becomes first green, then blue, and red 

 on heating. " Cannabene " prepared from this essence by Personne, was a 

 mixture. (J. Ch. S. LXVIIL, pt. I (1895), p. 623.) 



Charas, the natural exudation of the plant contains no chlorophyll. On 

 analysis, it was found to contain 33 per cent, of an oil, having the formula 

 C l3 H 24 2 . As this compound gives rise to all the symptoms of cannabis 

 poisoning, the main effects produced by the drug are due to the action of this. 



The ethereal extract from charas has yielded four distinct chemical com- 

 pounds :— 



1. A terpene, boiling at 160-180°. Yield 1*5 per cent. 



2. A sesquiterpene, boiling at 258-259°. Yield 2 per cent. 



3. A parffin (C 29 H 60 ), m. p. 63-64°. yield 015 per cent. 



4. A toxic red oil, C l8 H 24 2 , boiling at 265° under a pressure of 20 mm. 

 Yield 33 per cent, of the charas taken. This is a mixture of at least two 

 compounds having similar physical characters. One of these, of the formula 

 C 2 H 26 2 , has been isolated, and this has been named cannabinol. 



The physiological action of the terpenes closely resembles that of the 

 other members of this class, of which ordinary turpentine may be taken as 

 the type. In doses of 0*5 gram, they have very little effect and produce none 

 of the characteristic symptoms of cannabis action. The red oil, on the con- 

 trary, is extremely active, and taken in doses of 0*05 gram induces 

 decided intoxication followed by sleep. The symptoms produced by it are 

 peculiar to Cannabis indica, and as none of the other products appears to 

 possess this action, this substance must be regarded as the active constituent 

 of the plant. (J. Ch. S. 1896, T. 539 and 1899, T. 20.) 



On the standardisation of preparations of Indian Hemp. In 1908, Mr. 

 Hooper suggested a chemical method of valuing Indian hemp, and proposed 

 that the iodine value of the resinous constituents containing cannabinol 

 should be taken as a gauge of the activity. In the British Medical Journal 

 for May 20th, 1911, p. 1176, Messrs. Marshall and Wigner have examined 

 this method and shown that this method is of no value and could not 

 be used as a substitute for physiological standardisation. According to 

 them, the " acetyl number " should be used for determining the Standardisa- 

 tion. But in a report on the value of the " Acetyl number " by Messrs. 

 Marshall and Wood published in the same journal for June 1, 1912, p. 1234, 

 they came to the conclusion that the Acetyl number cannot be used as a 

 substitute for physiological standardisation. 



