PHARMACOLOGY OF CARISSA OVATA. 45 



The plant proved to be sufficiently distinctive from the normal 

 or coast form of Carissa ovata, R. Br., to warrant the Colonial 

 Botanist, Mr. F. M. Bailey, in describing it as a variety, viz., 

 stolonifera* The normal form of Carissa ovata is a common 

 plant about Brisbane ; observations and experiment show that it 

 very rarely develops the bitter poison of the western variety, and 

 if so, only in small amount. 



An alcoholic extract of the bark was made, and solutions in 

 water of this when injected into frogs rapidly killed them. The 

 muscles were pale and paralysed, and the heart stopped in systole. 

 Applied to the exposed hearts of frogs, pithed or under the 

 influence of Curara, it slowed and finally brought them to a 

 standstill in systole. It was then seen that the substance resembled 

 closely in its action Strophanthin and Ouabin, glucosides from 

 allied genera of the Apocynacese. 



A solution of the extract in water gave the following reactions: 

 copious precipitates with chloride of gold, acetate of lead and 

 sulphate of copper. Slight precipitates with acetic acid, dilute 

 sulphuric acid, tannic acid, mercuric chloride and ferric chloride 

 (black). No precipitate with ammonia, carbonate of soda, or 

 iodide of potassio-mercury. 



Referring to numerous works on Botany and Materia Medica, 

 I found the following mention of the medicinal use of a Carissa : 

 Under the heading Carissa in the " Treasury of Botany " there is 

 the following : — " Some of the species have medicinal properties, 

 being as bitter as Gentian. The bark of C. xylopicron, a native 

 of Mauritius and Bourbon, is used by the Creoles in diseases of 

 the urinary organs, while the wood, there called Bois amere, has 

 a like reputation. Small cups are made of it, in which water or 

 wine is allowed to stand till it acquires the flavour of the wood, 

 as in the bitter cups now so frequently used in this country." — 

 [M.T.M.] 



* Botany Bulletin, No. 9. 



