422 APOGYNEtE. 



spots ; the interior substance and inner surface (liber) is of a bright 

 buff. A transverse section shows the liber to be finely marked by 

 numerous small medullary rays. The bark is almost inodorous; its 

 taste is purely bitter and neither aromatic nor acrid. 



Microscopic Structure— The cortical tissue is covered with a thin 

 suberous coat ; the middle layer of the bark is built up of a thin walled 

 parcnchyme, through which enormous, hard, thick-walled cells are scat- 

 tered in great numbers and are visible to the naked eye, as they form 

 large irregular groups of a bright yellow colour. Towards the inner part 

 these stone-cells disappear, the tissue being traversed by undulated 

 medullary rays, loaded with very small starch grains ; many of the other 

 parenchymatous cells of the liber contain crystals of calcium oxalate. 

 The longitudinal section of the liber exhibits large but not veiy 

 numerous laticiferous vessels, containing a brownish mass, the concrete 

 milk-juice in which all parts of the tree abound. 



^ Chemical Composition — The first attempts to isolate the active 

 principles of this bark were made by two apothecaries, Scharlee at 

 Batavia' (1862) and Gruppe at Manila^ (1872), 



In 1875 Jobst and Hesse exhausted the powdered bark with 

 petroleum ether, and then extracted, by boiling alcohol, the salt of an 

 alkaloid,^which they called Ditamine. After the evaporation of the 

 alcohol, it is precipitated by carbonate of sodium and dissolved by 

 ether, ^from which it is removed by shaking it with acetic acid. 

 Ditamine as again isolated from the acetate forms an amorphous and 

 somewhat crystalline, bitterish powder of decidedly alkaline character; 

 the barks yields about 002 per cent, of it. 



From the substances extracted by means of petroleum ether, as 

 above stated, Jobst and Hesse further isolated (1) EcJiicaoutchin, 



xi U , an amo 



acicular crystals, _. _ „^.__.„ 



scales, melting at 170=° (4) Echitein^'mV'^6^' which forms"' rhombic 

 prisms, melting at 195°; (5) Echiretin, C^'H^^O^ an amorphous 

 substance meltino- at 52° C. 



rphous yellowish mass ; (2) Echiccrin, C'E^O', forming 

 , melting at 157^ C; (3) Echitin, C^^H^^O^, crystallized 



Ecljicaoutchin may be written thus: (CHyO', cchicerin (CH)O-, 

 echnetm {Q^WyO^-, these formulae at once point out how nearly tlie 

 three last named substances are allied. They are probably constituents 

 of the milky-juice of the tree. 



Lastly, Jobst and Hesse pointed out the existence of another 

 alkaloid in Dita bark. 



Harnack (1877) on the other hand is of the opinion that it contains 

 only one alkaloid, which he terms Ditwine. He used the alcoholic 

 extxact of the bark which he treated with ether to which he added a 

 little ammonia. By this process ditamine of Jobst and Hesse wouia 

 have been removed, but Harnack suggests that only a little ditame 

 IS dissolved by ether. He then mix?d the extract with potash ana 



;ted It with alcohol, which afforded crystals of ditainc, answering 

 to the formula Q^m^o^'^0'. j^g physiological action is nearly the sawe 

 as that of curare. Ditaine is but sparingly soluble in ether or peti^- 



^'^^T^^''^-^^'^<^l-lndic,x.{l8m ^ Jahreshericht of Wiggers auJ ^use- 



manu, 1873. 51. 



exh{ 



4I;; ^^"^ ^'^^^^'^ der Pharmacie, 212 (1878) 



