RADIX ACOXITI. 9 



and is giowing out of it on one side. This second root has a bud at 

 the top which is destined to produce the stem of the next season. It 

 attains its maximum development at the latter part of the year, the 

 parent root meanwhile becoming shrivelled and decayed. This forai of 

 growth is therefore analogous to that of an orchis. 



The dried root is more or less conical or tapering, enlarged and knotty 

 at the summit which is crowned with the base of the stem. It is from 

 2 to 3 or 4 inches long and at the top from i to 1 inch thick. The 

 tuber-like portion of the root is more slender, much shrivelled longi- 

 tudinally, and beset with the prominent bases of rootlets. The di-ug 

 is of a dark brown; when dry it breaks with a short fracture exhibiting 

 a white and farinaceous, or brownish, or grey inner substance some- 

 times hollow in the centre. A transverse section of a sound root shows 

 a pure white central portion (pith) which is many-sided and has at each 

 of its projecting angles a thin fibro-vascular bundle. 



In the fresh state the root of aconite has a sharp odour of radish 

 which disappears on drying. Its taste which is at firet sweetish soon 

 becomes alarmingly acrid, accompanied with sensations of tingling and 

 numbness. 



Microscopic Structure — The tuberous root as seen in a transverse 

 section, consists of a central part enclosed by a delicate cambial zone. 

 The outer part of this central portion exhibits a thin brownish layer 

 made up of a single row of cells {Kei^nschekle of the Gennans). This is 

 more distinctly obvious in the rootlets, which also show numerous, 

 scattered, thick-walled cells of a yellow colour. 



The fibro-vascular bundles of aconite root are devoid of true 

 ligneous cells ; its tissue is for the largest part built up of uniform 

 parenchymatous cells loaded with starch granules. 



Chemical Composition — Aconite contains chemical principles 

 which are of great interest on account of their virulent effects on the 

 animal economy. 



The first to be mentioned is Aconitine, a highly active crystallizable 

 alkaloid, furnishing readily crystallizable salts. It is accompanied by 

 another active alkaloid, Pseudaconitine, which is crystallizable, but 

 yields mostly amorphous salts. According to the admirable researches 

 of Wright and Luff"/ aconitine may be decomposed according to the 

 following equation : — 



C^H^NO'- . OH- = C'H'^0- . C^H^NO", 



Aconitine. Benzoic acid. Aconine. 



and pseudaconitine breaks up in accordance with the equation : 

 C^H^NO" . OH- = (JWO' . C^H^NO' 



Pseudaconitine. Dimethyl- Pseudaconine. 



protocatechuic acid. 



The decomposition of aconitine, as well as of pseudaconitine, may 

 be performed by means of mineral acids, alkaline solutions, or also by 

 heating the bases with water in sealed tubes. The two alkaloids, 

 Aconine and Pseudaconine, appear to be present already in the roots 

 of Aconitum; they, moreover, contain two other alkaloids of less 



^Pharm. Joum. 1875 to 1878, also Tear- Comparative qualitative reactions of Aconi- 

 hoolc of Pharmacy, the results being sum- tine, Aconine, Pseudaconitine, and Psen- 

 marized in the Yearbook for 1877, 466.— daconine, see Yearbook (1877) 459. 



