358 JO URNAL, BOMB A Y NA TURAL HISTOR 7 SOCIETY, Vol. IX. 



sweetish, but acrid and hot taste, easily fusible, partially volatile, scanti- 

 ly soluble in cold, freely in boiling water, very soluble in alcohol and 

 ether, in the concentrated acids, and in alkaline solutions, with which 

 it strikes a deep red colour ; or with hydrate of alumina* or 

 subacetate of lead a crimson-red coloured precipitate is formed, which 

 constitutes a very valuable and delicate test, available in many 

 medico-legal inquiries."! I n the light of these researches of 

 O'Shaughnessy it is important to remember that happily for toxico- 

 logists, Plumbagin is one of the few vegetable poisons which can be 

 detected by chemical analysis as a matter of certainty. u Two 

 grains of the powdered bark," says Dr. O'Shaughnessy, " may be 

 detected in a pint of a mixture of milk, blood and various articles 

 of food." 



The careful researches of Dr. O'Shaughnessy are further emphasized 

 by Dr. Dymock and his confreres! in describing the chemical com- 

 position of Plumbago rosea. They say that " the activity of the drug- 

 depends upon the presence of Plumbagin" It crystallizes, they add, 

 u in delicate needles or prisms, often grouped in tufts ; has a styptic 

 saccharine taste ; melts very easily, and partly volatalizes unaltered 

 when heated. It is neutral, nearly insoluble in cold, more soluble in 

 boiling water, very soluble in alcohol and ether. It dissolves with 

 yellow colour in strong sulphuric acid, and fuming nitric acid, and is 

 precipitated by water in yellow ijocks. Alkalies change the colour of the 

 solution to a fine cherry-red ; acids restore the yellow colour." The 

 extreme importance of these tests, from a toxicological point of view, is 

 my only apology for thus extensively reproducing the remarks 

 contained in the " Pharmacographia Indica " of Dr. Dymock and his 

 colleagues. Dr. Lyon § makes a few remarks which may well be 

 reproduced here :— " Plumbagin treated with caustic potash solution 

 dissolves, forming a bright crimson liquid. Hydrochloric acid added 

 to this changes the colour to yellow, and on standing the liquid deposits 

 yellow flocculi of Plumbagin, which may be separated by shaking the 



* According to modem chemical nomenclalure Aluminium tribydrate and tribasic acetate 

 of lead respectively. 

 t O'Shaughnessy's Bengal Dispensatory, p. 509, 1841. 

 X Pharmacographia Indica, vol. ii, p. 332, 1891. 

 § Medical Jurisprudence for India, p. 219, 1889. 



