CORTEX ALSTONLE. 421 



forces in question the moment the drop flattens down by its gi-avity 

 upon the surface of the water. The adhesion of the liquid surfoce 

 tends to spread out the drop into a him, the cohesive force of the 

 particles of the drop strives to prevent that extension, and the 

 resultant of these forces is a figure which Mr. Tomlinson believes to 

 be definite for every independent liquid. The figure thus produced 

 is named the cohesion-figure. 



So far as our experience goes, the processes hitherto recommended 

 for testing olive oil (and there are several that we have not mentioned) 

 are only available in cases where the adulteration is considerable, and 

 are quite insufficient for discovering a small admixture of other oils. 

 How little they are appreciated, may be inferred from the fact that the 

 Chamber of Commerce of Nice^ offered a reward of 15,000 francs 

 (£G00) for a simple and easy process for making evident an admixture 

 with olive oil of 5 per cent, at least of any seed-oil. 



APOCYNE^. 



CORTEX ALSTONIiE. 



Cortex Alstonice scholaris ; Dita Bark;^ Alstonia Bark. 



Botanical Origin — Alstonia^ scholaris R. Brown (Echites scholaris 

 L.), a handsome forest tree, 50 to 90 feet in height, common throughout 

 the Indian Peninsula from the sub-Himalayan region to Ceylon and 

 Burma; found also in the Philippines, Java, Timor and Eastern Australia, 

 likewise in Tropical Africa. It has oblong obovate leaves, in whorls of 

 5 to 7, and slender pendulous pods a foot or more in length. 



History — Saptachhada and saptaparna (literally seven-leaf), occur- 

 ring in early Sanskrit epic poetry and also in Susruta, are ancient names 

 of Alstonia (Dr. Rice). Rheede^ in 1678 and Rumphius^ in 1741 described 

 and figured the tree, and mentioned the use made of its bark by the 

 native practitioners. Rumphius also explained the trivial name 

 scholaris as referring to slabs of the close-gi'ained wood which are used 

 as school-slates, the letters being traced upon them in sand. The tonic 

 properties of the bark were favourably spoken of by Graham in his 

 Catalogue of Bombay Plants (1839), and further recommended by Dr. 

 Alexander Gibson in 1853.* The drug has a place in the Fharmacopoeia 

 of India, 1868. 



Description — The drug, as presented to one of us by the late Dr. 

 Gibson and by Mr. Broughton of Ootacamund, consists of irregular 

 fragments of bark, ^ to | an inch thick, of a spongy texture, easily 

 breaking with a short, coarse fracture. The external surface is very 

 uneven and rough, dark grey or brownish, sometimes with blackish 



^ Annales de Chimie et de Physique, (1740-1760) in the University of Edin- 



March, 1869. 309. burgh.— The plant is figured in^Bentley 



^ From Dita, the name of the tree in the and Trimen, Med. PL part 25 (1877). 



island of Luzon. * Hortus Malabaricus, i. tab. 45. 



* So named in honour of Charles Alston, " Herb. Amboin. ii. tab. 82. 



Professor of Botany and Materia Medica " Pharm. Journ. xii. (1853) 422. 



