BY J. H. MAIDEN. 681 



is added to the acid solution, a precipitate is formed, as in the 

 case of tragacanth. 



From the above and other tests it was found that the gum 

 possesses properties very similar to those of tragacanth. At the 

 same time, the quantity of gum at my disposal is so very small 

 that I have been unable to make practical tests of its value as a 

 substitute for that well-known gum. It is proper to state that 

 the gum of Mezoneurum scortechinii (or even of its allied species 

 br achy car piim) can never be sufficiently abundant to form an 

 article of commerce. It may be mentioned that tragacanth is 

 also the product of a leguminous genus (Astragalus), which is 

 not, however, closely related to Mezoneurum. 



The composition of this sample of Barrister Gum may be stated 

 as follows : — 



Soluble in cold water* ... ... 16*5 



Soluble in acids ; insoluble in alkalies* 68-57 



Moisture 10-95 



Ash 3-98 



100-00 

 Both the kino and the gum were collected in the Richmond 

 River district by Mr. W. Bauerlen, Botanical . Collector to the 

 Technological Museum, and I have been helped in the examina- 

 tion of them by my laboratory-assistant, Mr. H. G. Smith. 



* This gum appears to contain neither Arabin nor Metarabin. The 

 soluble and insoluble constituents of tragacanth and some tragacanthoid 

 gums are discussed in a paper by the author — " Sterculia Gum : its Simi- 

 larities and Dissimilarities to Tragacanth " (Pharm. Joum. [3], xx., 381) — 

 to which the reader is referred. 



