HEMLOCK 113 



the proportion of coniine rapidly diminishes. Commercial fruits 

 yield from 0-5 to 1-3 per cent, of coniine. 



It is accompanied in the fruit by small quantities of methylconiine, 

 which is oily and resembles coniine, and by conhydrine, which is 

 colourless and crystalline. Ethyl piperidine and pseudoconhydrine 

 are also present. 



Pure coniine, C 8 H 17 N, is a-propyl-piperidine. It is a colourless, oily, very 

 poisonous liquid with an extremely unpleasant odour. It boils at 163'5 with- 

 out decomposition in an atmosphere free from oxygen ; but exposed to the 

 air, even at ordinary temperatures, it rapidly assumes a brown colour. It 

 yields crystalline non- volatile salts. It may be produced from a-picoline, 

 C 5 H 4 (CH 3 )N, one of the constituents of coal tar, by heating it to 250 for 10 hours 

 with acetic aldehyde, by which it is converted into a-allyl pyridine C 5 H 4 (C 3 H 5 )N ; 

 this by reduction with sodium yields coniine C 5 H 9 (C 3 H 7 )NH. Coniine thus 

 prepared is, however, optically inactive, whereas natural coniine is dextro- 

 rotatory ; it can be separated into the dextro- and lee vo -rotatory alkaloids 

 by inducing crystallisation of the tartrate by means of a crystal of natural 

 coniine tartrate. 



Assay. Percolate 10 gm. of the finely produced fruit with 70 per cent, alcohol 

 until exhausted, add 20 c.c. N/10 sulphuric acid and evaporate off, the alcohol. 

 Transfer to a separator, wash twice with chloroform, make alkaline with solution 

 of potash and shake out with three successive 5 c.c. of chloroform. Transfer 

 the alkaloids to acidified water and back to chloroform. Repeat this purifica- 

 tion twice. Finally shake the chloroformic solution of the alkaloids with three 

 drops of fuming hydrochloric acid, wash the separator with a little alcohol, 

 evaporate, dry at 90 and weigh. The weight of the alkaloidal hydrochlorides 

 multiplied by 0-777 gives the weight of alkaloid in 10 gm. of the fruit. 



Uses. Hemlock is used in spasmodic and convulsive diseases, 

 such as tetanus, chorea, and epilepsy ; in asthma, whooping-cough, 

 and spasmodic affections of the larynx. Coniine depresses the 

 medulla and motor nerve endings, excessive doses resulting in death 

 from respiratory paralysis. 



CORIANDER FRUITS 



(Fructus Coriandri) 



Source, &C. The coriander, Coriandrum sativum, Linne (N.O. 

 Umbelliferce), is an erect herbaceous annual that has become naturalised 

 throughout temperate Europe. It is cultivated principally in Russia, 

 Thuringia, Moravia, and Hungary, as w r ell as in northern Africa, 

 Malta, and India. The whole plant, and especially the unripe fruit, 

 is characterised by a strong disagreeable odour, whence the name 

 coriander (from the Greek /copis, a bug). As the fruit ripens, this 

 gives place to an agreeable aroma, and the plant is then cut and 

 thrashed. It has been cultivated for many centuries for use as a 

 spice. 



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