THE POISONOUS PLANTS OF BOMBAY. $59 



acidified fluid with ether. An alcoholic solution of Plumbagin 

 gives a crimson precipitate with solution of basic acetate of lead." Dr„ 

 Lyon further adds an important note which is useful for analytical pur- 

 poses : — " A colouring matter obtained from rhubarb root gives, with 

 caustic potash solution, a crimson colour similar to that given by 

 Plumbagin. An alcoholic solution of it, however, gives, with acetate 

 of lead solution, an orange precipitate, not a crimson precipitate like 

 Plumbagin." 



There is yet another work, and a more recent one, 1 should like to 

 refer to in connection with the active principle hitherto known as Plum- 

 bagin. It is the Dictionary of the Active Principles of Plants, compiled 

 and published by Charles B. Sohn, F.I.C.,F.C.S., last year. At page 10 

 of this valuable work Dulong's Plumbagin is otherwise named Ophioxylin 

 (Ci6 Hia 06 , or C 4 8 H 39 Ois). It is said by Sohn to resemble Juglone* 

 It is one of the active principles, found in some of the representatives of 

 the Natural Order Apocynaceat, as, for instance, Rauwolfia (Ophioxylon) 

 serpentina and trifoliata. It is seen in the form of orange crystals of 

 the tetragonal system, the melting point of which is 71'8°. No 

 wonder, then, that in India the active principle contained in those roots 

 is of an evanescent nature where the normal temperature is, as a rule, 

 above the melting-point above indicated, except in the cold weather. 

 This leads me to consider here the following remark made in the 

 " Pharmacographia Indica" (pp. 332t333) by Dr. Dymock and his 

 colleagues, namely : — " M. Greshoff, who has been investigating the 

 chemistry of the medicinal plants of Java * * * , is of opinion that 

 the roots (supposed to be from Rauwolfia serpentina) examined by 

 Wefers Bettink * * * were really those of Plumbago rosea. Pro- 

 fessor Bettink extracted with chloroform a yellow crystalline princi- 

 ple, apparently the Plumbagin of Dulong. Had M. Greshoff the 

 benefit of Sohn's recent researches, I am positive he would have come 

 to the conclusion that they both contain the same active principle ; 



* Note.—" Vogel and Reischauer discovered a substance which crystallized in reddish- 

 yellow needles in the green outer shell of the unripe walnut (Juglans regia), and owe to it 

 the name of nucine, and afterwards changed to juglone. C. Eeischauer then pointed out that 

 this substance was probably identical with the regianine which had been prepared from the 

 nutshells by Phipson, and this was confirmed by the latter chemist."— Treatise on Chemistry 

 Koscoe and Schorlemmer, vol. iii, Organic Chem., part vi, p. 137. 



