KADJX BELLAi)uNN/E. U7 



Microscopic Structure-There is a considerable structural difror- 

 ence between the main root and its branches, the former alone contain- 

 ing a distinct pith. This pith is included in a woody circle, traversed 

 by narrow medullary rays. In the outer part of the woody circle, 

 parenchymatous tissue is more prevalent than vascular bundles. The 

 transverse section of the branches of the root exhibits a central vascular 

 bundle instead of a medullary column. The outer vascular bundles 

 show no regular arrangement; and medullary rays are not clearly 

 obvious in the transverse section. 



The woody parts, both of the main root and its branches, contain 

 very large dotted vessels accompanied by a proscnchymatous tissue. 

 The cells of the latter, however, are always thin-walled ; the absence of 

 proper so-called ligneous tissue explains the easy fractvu-e of the root, 

 fe'ometnnes the prosenchymc in which the vessels are imbedded assumes 

 a brownish hue and a waxy appearance, and such parts exhibit a very 

 n-regular structure. 



_ In the cortical portion of belladonna root, many of the cells of the 



middle layer, and likewise some of the central parts of the root, are 



baded witli extremely small octahedric crystals of calcium oxalate. 



But most of the parenchymatous cells are filled up with small starch 

 granules. 



Chemical Composition — In 1833 Mein prepared from the root, 

 and Geiger and Hesse from the herb, the crystal lizable alkaloid 

 Atropine, _ The researches of Lefort (1872) have proved that the roots 

 contani it in very variable proportions, the young being much richer 

 111 alkaloid than the old.^ The maximum proportion obtained was OG 

 per cent.; this was from root of the thickness of the finger. Large old 

 j-oots, 7 or 8 years of age, afford from 0-25 to 031 per cent. They have 

 besides a smaller proportion of bark than young roots, and it is chiefiy 

 in tlie bark that the alkaloid appears to reside. Manufacturers of 

 atropine employ exclusively the root. 



Liidwig and Pfeiffer (18(31), by decomposing atropine with potassium 

 ciironiate and sulphuric acid, obtained benzoic acid and propylamine. 

 Uther products are formed when atropine is treated with strong hydro- 

 ciioric acid, baryta water or caustic soda, thus— ^^jy>^««^, C'H^iS'O' 

 + HO = Tropic Acid, C'W'O' + Tropine, C'H^^NO. 



Tropic acid, C^H^C (OH) | qqqjj , being further boiled with tlie 



same agents is converted into atropic acid, C"H^C | ^JJ^j^, which, 



^specially by using hydrochloric acid, is gradually transformed into 

 isotropic acid. Both these acids are isomeric to cinnamic acid, C'H'O', 

 J^ut otherwise remarkably dissimilar. 



Iropinc is a strongly alkaline body, readily soluble both in water 



aJid alcohol, and furnishing tabular crystals by the evaporation of its 



^lution in ether. Neither tropine nor tropic acid, it is stated by 



raut (1808), is present in the leaves and root of belladonna. 



^ubschinann (18o8) detected in belladonna root a second l)ut un- 



crystallizable alkaloid, called Belladonmne ; it hiis a resinous aspect, 



8 distinctly alkaline, and when heated emits, like atropine, a peculiar 



' For Lefort'a process for estimating atropine, see p. 458. 



