FOLIA HYOSCYAMI. 4G5 



which are far richer in it than the leaves.^ The seeds are deprived of 

 the fatty oil (20 per cent.) and treated with spirit of wine containing 

 sulphuric acid, which takes out the hyoscyaniine in the form of sul- 

 phate. The alcohol is then evaporated and tannic acid added ; the 

 precipitate thus obtained is mixed with lime and exhausted with 

 alcohol. The hyoscyamine is again converted into a sulphate, the 

 aqueous solution of which is then precipitated with carbonate of 

 sodium, and the alkaloid dissolved by means of ether. After the evapo- 

 ration of the ether, hyoscyamine remains as an oily liquid which after 

 some time concretes into wart-like tufted crystals, soluble in benzol, 

 chloroform, ether, as well as in water. Hohn and Reichardt assign 

 to hyoscyamine the formula C^^H^O^ The seeds yield of it only 005 

 per cent. 



Hyoscyamine is easilj' decomposed by caustic alkalis. By boiling 

 with baryta in aqueous solution, it is split into Hyoscine, C*H'^N, and 

 Hyoscinic Acid, C?H'"0^ The foi-mer is a volatile oily liquid of a 

 narcotic odour and alkaline reaction. By keeping it over sulphuric acid 

 it crystallizes and also yields crystallized s<ilts; hyo.scine may be clo.sely 

 allied to conine, CfH'^N. Hyoscinic acid, a crystallizable substance 

 having an odour resembling that of empj-reumatic benzoic acid.- It 

 melts, according to Hohn, at 105°; tropic acid (see p. 457), melting at 

 118°, agrees so very nearly with hyoscinic acid that further researches 

 will probably prove these acids to be identical. 



Another process for extracting hyoscyamine is due (1875) to 

 Thibaut. He removes by bisulphide of carbon the fatty oil from the 

 powdered seeds, and exhausts them with alcohol slightly acidulated by 

 tartaric acid. The alcohol being distilled off, the author precipitates 

 the alkaloid by means of a solution containing 6 per cent, of 

 iodide of potassium and 3 per cent, iodine. By decomposing the 

 precipitate with sulphurous acid, hydroiodic acid and sulphate of 

 hyoscyamine are formed. The latter is dried up at 35° with magnesia 

 and the hyoscyamine extracted by alcohol or chloroform. The crystals 

 melt at 90°. Thibaut found the alkaloid thus prepared from seeds 

 differing from that yielded by the leaves, the latter having a somewhat 

 strong odour. 



Attfield^ has pointed out that extract of henbane is rich in nitrate 

 of potassium and other inorganic salts. In the leaves, the amount of 

 nitrate is, according to Thorey,* largest before flowering, and the same 

 observation applies to hyoscyamine. 



Uses — Henbane in the form of tincture or extract is administered 

 as a sedative, anodyne or hypnotic. The impropriety of giving it in 

 conjunction with free potash or soda, which render it perfectly inert, 

 has been demonstrated by the experiments of Garrod.^ Hyoscyamine, 

 like atropine, powerfully dilates the pupil of the eye. 



Substitutes — Hyoscyanius albus L., a more slender plant than H. 



* From the experiments of Schoonbroodt said chemists. — F. A. F. July 1871. 

 (1868), there is reason to believe that the * Phann. Journ. iii. (18C2) 447. 



active principle of henbane can be more * Wiggers and Husemann, Jahresbericht, 



easily extracted from the /resA than from 1869. 5ti. 



the dried plant. » Pharm. Journ. xvii. (1858) 462 ; xviii. 



* I have had the opportunity of examining (1859) 174. 

 the above substances as prepared by the 



2g 



