BY J. H. MAIDEN. 39 



though containing varying proportions of metarabin, which sub- 

 stance causes them to swell in cold water. The gum of P. 

 murrayi would form a valuable substitute for gum arable, and it 

 would be a valuable minor industry for this country if it were 

 procurable in large quantities. 



All the gums possess some odour, obtained from the barks, and 

 isolation of the odoriferous bodies could be best carried out by 

 analysis of tlie bark. This odoriferous principle in the Araliacere, 

 and reminding one of the Umbelliferse, has long been known. 

 "Most of the species have a very strong smell of aniseed and 

 celery, — hence the name of 'Celery-tree' is given to Panax 

 (Notliopanax) elegans by the Queensland colonists." (Seemann, 

 Flora vitiensis, 114). 



The ash of Panax gums principally consists (in my samples) of 

 lime, magnesium, and potassium, with a trace of iron, and 

 although the bases were present principally as carbonates, both 

 sulphuric and phosphoric acids were found. Quantitative deter- 

 minations of the different constituents of the ash were not 

 made, with the exception of phosphorous pentoxide, the percentage 

 of Pj O5 in the ash of P. elegans being 'GGQ, 



The gums may therefore be considered as principally the 

 calcium, magnesium and potassium salts of arable acid. 



