142 THE OCCURRENCE OF A GUM IN ECHINOCARPUS AUSTRALIS 



Its composition may be stated as follows : — 



Soluble in cold water (arabin) 12*05 



Soluble in -1% soda (metarabin) ; yields 



arabin on precipitation with alcohol 39*8 



Vegetable mucilage of Dragendorff; in- 

 soluble in *1% acid, -1% soda solution, but 



soluble in potash solution 20*91 



Water 1873 



Ash* 4-486 



95-976 



Composition of the Ash. 



Soluble in water : — 



Potassium sulphate 



Insoluble portion : — 



Calcium carbonatef 3-769' 



Magnesium carbonate *281 



Alumina trace 



Ferric oxide tracer 



Total 



•436 



4-05 



4-486 



* Placed in percentage composition for convenience. 



t Probably originally existing as oxalate, as calcium oxalate was found 



in the original gum. 



