522 HENBANE 



HYOSCYAMUS 



HYOSCYAMUS OR HENBANE LEAVES. The fresh leaves and 

 flowers, with the branches to which they are attached, 

 of Hyoscyamus niger ; also the leaves and flowering 

 tops, separated from the branches and carefully dried. 

 Collected from the flowering biennial plants (B.P.). 

 Nat. Ord. Solanaceae. 



Henbane grows wild in most parts of this country, and is 

 cultivated at Mitcham and Hitchin. The large, sinuate, 

 usually decurrent yellow-brown leaves are rough, hairy, and 

 clammy, with a foetid, narcotic odour, and a nauseous, 

 bitter taste. There are two varieties, an annual and a 

 biennial ; the latter alone recognised by the B.P., is larger, 

 stronger, more branched, clammy, and active. One hundred 

 pounds of the fresh plant when dried weigh 14 Ibs., and yield 

 about 4 Ibs. of extract. 



The active principle, hyoscyamine (C 17 H 23 N0 3 ), in its 

 impure form is an oily liquid, becoming brown on ex- 

 posure, but it can be slowly crystallised into colourless, 

 translucent needles. It is soluble in 120 of water, and 

 readily dissolves in alcohol, chloroform, and dilute acids. 

 It resembles daturine, the active principle of Datura 

 stramonium, is identical with duboisine, the active alkaloid 

 of Duboisia myoporoides, and is isomeric with atropine. 

 Its relationship to atropine is very close, and, in fact, it 

 is quite easily converted into atropine. It is decomposed, 

 and its physiological action neutralised by caustic alkalies. 

 Henbane also contains hyoscine, or scopolamine, which is 

 a cerebral and spinal sedative. 



ACTIONS AND USES. Hyoscyamus closely resembles bella- 

 donna and stramonium. Locally applied, it paralyses the 

 endings of sensory nerves. It dilates the pupil, although 

 not so certainly and fully as atropine. Full doses of the 

 drug or its alkaloid stimulate the cerebral centres to a some- 

 what less extent than atropine, and paralyse the ends of 

 motor nerves. There are produced dryness of the mouth, 

 restlessness, general convulsions, paralysis, and stupor, 

 alternated with a peculiar form of delirium, in which a 

 constant desire for movement is accompanied by lassitude, 



