N. 0. RHAMNEJE. 333 



Part used : — The root-bark. 



Uses: — The powdered root-bark is carminative, stomachic, 

 tonic and stimulant ; useful in atonic dyspepsia, debility and 

 slight cases of fever (Moodeen Sheriff). 



The powdered bark (mixed with gingelly oil) is also said 

 to be sometimes used in South India as an external application 

 for itch and other skin diseases (Watt). 



Ventilago Madraspatana. 



On treating this dye-stuff with carbon bisulphide five crystalline sub- 

 stances are extracted, together with a wax and a resinous colouring 

 matter. 



1. A substance of the formula C 16 H 12 5 . This crystallises in long, 

 orange-red needles, melting at 200° ; it sublimes at higher temperatures, 

 partially carbonising. Its alkaline solutions have a purple tint, and the 

 corresponding salt can be obtained in the form of violet-colored needles 

 sparingly soluble in alcohol. There is a great deal of similarity in appear- 

 ance, properties, and melting point between emodin from Rhamnus frangula 

 and this substance. They are probably identical. 



2. A substance of the formula C 16 -H 14 4 (A). This forms long, colourless 

 needles, which decompose at about 260° before melting ; it is soluble in alka- 

 line solutions with a yellowish brown coloration. 



3. A substance of the formula C l6 H 14 4 (B). This crystallises in pale 

 yellow needles melting at 173°. With acetic anhydride, it yields what is 

 probably a triacetyl compound melting at 227-229°, the alcoholic solution of 

 which has a strong blue fluorescence. Tt dissolves in alkalis forming yellow- 

 ish brown solutions which on long exposure to air become red, and on treat- 

 ment with acid yield a precipitate of emodin methyl ether. 



4. A substance of the formula G 16 H 3 8 . This is an orange-red, crystalline 

 powder, which, when heated, begins to darken at 260°, and melts and carbon- 

 ises at 275-280°. It is distinguished from the preceding substances by its 

 sparing solubility in most solvents. Solutions of the alkalis dissolve it with 

 an orange-red coloration, and it yields an acetyl derivative, C l0 -H 7 O 8 (C 2 H 3 0), 

 which crystallises in yellow needles melting and decomposing at 216-220°. 



5. A substance of the formula 17 H 12 5 . This is a chocolate-colored, 

 crystalline powder. When treated with dilute alkali, it dissolves with a yel- 

 low coloration, but on exposure to air the solution deposits a blue, amorphous 

 precipitate, and it therefore appears to contain in its molecule a reduced 

 quinone group. 



6. The wax (C 9 H l6 0) n , consists of nearly colourless, minute needles, 

 melting at 72°. 



