194 MESEMl'.KIANTHEMUM MAIIONI, N.E.BR. 



the roots contain a quantity of oxalates equivalent to about 3 per 

 cent, of oxalic acid, and that there is little doubt that the 

 poisonous effects produced by the roots are due to these con- 

 stituents. 



The following is an extract from the report of the Imperial 

 Institute : — 



The sample weighed about 7 lbs., and consisted of small 

 twisted pieces of the roots, which were covered with knotted 

 rootlets. The roots were light-brown externally, but white 

 internally, and were hollow and shrivelled. 



A microscopical examination of the material showed that 

 parts of the root were covered with a fungus, to the activity of 

 which their fermenting power was due. 



On chemical examination the roots were found to contain a 

 quantity of oxalates, equivalent to about 3 per cent, of oxalic 

 acid. 



Oxalic acid and its salts are poisonous, and the injurious 

 effects resulting from the habitual use of beverages prepared by 

 the acid of this root are no doubt due to the oxalates present. 



In view of these results it is not desirable that the roots of 

 M esembrianthcmum Mahoni should be used as a substitute foi 

 yeast in making bread. Their activity in inducing fermentation 

 seems to vary considerably in different specimens, so that it may 

 be necessary occasionally to use an unduly large proportion of the 

 powdered root in bread-making, and in these circumstance? 

 poisoning might ensue. 



Since the above report was received, the writer has found 

 that the roots of another species of M esembrianthcmum (Burtt- 

 Davy, No. 12,265) are a ^ s0 llsef l as a substitute for yeast in the 

 Cape Province. This species grows in the Karoo, near East- 

 poort, Bedford Division, where it is known as T'Kerriemoru ; 

 the root is peeled, dried and powdered, and mixed with prickly 

 pear juice or honey, and when fermented the material is used to 

 make bread rise. In the absence of flowering specimens, I have 

 not yet been able to determine the species.* 



Andrew Smith states that a species of M escmb riant hemum 

 ("probably M. beUidiflorum ") is used by the Hottentots to 

 soften skins for clothing. " They make a paste of the plant, and 

 work in the juice into the skin with a stone." 



In a valuable paper on " Kaffir-beers, their Nature and 

 Composition," I to which my attention has only just been called, 

 Dr. Juritz notes the following plants also used in the preparation 

 of Kaffir-beers : — 



Lineum capense Thunb. ; 



M esembrianthcmum stellatum Mill. ; 



Anacampseros ustulata E. Mey. 



* The plants have since flowered, and have been determined by Mrs. 

 F. Bolus as M. stellatum Mill. 



t Agricultural Journal (Cape), vol. XXVIII., 1906 No. 1, pp. 35-47. 



