POISONOUS PROPERTIES OE 

 MESEMBRIANTHEMUM MAHONI, N.E.Br. 



By Joseph Burtt-Davy, F.L.S., F\R.G.S. 



In December. 1909, specimens of Mcscmbrimithemum 

 MaJioni N.E.Br., were received from Mr. P. B. Carlisle, of 

 Hopefield, P.O. Lawley Station, Witvvatersrand, with the fol- 

 lowing information: — 



The plant is chiefly found growing on kopjes. Certain 

 Natives make a preparation from the root, which they use as a 

 fermenting agent for the manufacture of the drink popularly 

 known as " khadi," and as the rising principle for bread. The 

 bark is scraped from the root, and the residue dried and pow- 

 dered. It is said, however, that the root contains some poisonous 

 principle that in time proves injurious to the khadi-drinker. " I 

 should like, therefore, to know if this latter is so, and if so, to 

 what extent it would be dangerous to use the powdered prepara- 

 tion as a ferment, either for liquids or for bread." 



In a further communication Air. Carlisle stated that the 

 Natives to whom the locality of the root is known are very 

 jealous of the secret; they fear that if Europeans get to know 

 of it the plants will be destroyed in the interests of temperance. 

 Khadi, he added, is only used, he believes, by certain tribes, and 

 it is only to them that the plant is known ; he had personally 

 searched unsuccessfully for it. There seems to be no doubt as 

 to the poisonous nature of the root, unprepared. It is said f o 

 produce a " bloated " sensation. 



In January, 1910, Mr. Carlisle described the method of 

 preparation of the powder for bread-making, as follows : — 



Scrape the bark off the root ; leave the root to dry (this 

 takes two to three days in dry weather, or about five in wet) ; 

 powder with a mortar as finely as possible ; soak for one day in 

 water; draw off the water, and dry, or if it is needed in haste, it 

 can be used damp. 



It is then used as follows: Mix a teaspoonful of powder 

 with a teaspoonful of sugar ; add about a wineglass of lukewarm 

 water ; in about a minute the mixture will begin to effervesce ; 

 when this occurs add a saucerful of flour and enough lukewarm 

 water to make a thick batter. Keep this in a warm place till it is 

 "working" well (about two hours or longer); then take flour 

 (any amount up to, say, 20 lbs.) ; put the sponge in the flour, 

 and mix salt and lukewarm water as usual ; mould into loaves, 

 and set to rise (about three hours). Bake as usual. The rising- 

 time may be much longer if convenient. " This bread does no* 

 go sour." 



I arranged with Mr. Carlisle for the supply of 25 lbs. weight 

 of the dried roots. This material was forwarded to the Director 

 of the Imperial Institute in June, 1910, with a request that the 

 poisonous properties be investigated. A report was received, 

 under cover of a letter dated December, 191 1, which stated that 



