58 



diameter. It is transparent, of hyaline or liorny appearance, 

 and from colourless up to pale amber. It reminds one irresistibly 

 of Sterculia gum, and it is not a little interesting to find that the 

 similarity also extends to their chemical composition. Following 

 is an analysis : — 



Arabin... ... ... 15-02 



Pararabin ... ... 63*4 



Moisture 21-0 



Ash 1-4 



A comparatively high percentage of arabin in a Proteaceous 

 gum is a sign of its newness, and causes the formation of a viscid 

 solution in water. When these gums have been exposed to the 

 weather, more or less of the arabin is washed out, and the re- 

 maining soluble portion can be filtered off with great facility. 



Persoonia linearis, Andr.j B. FL, v. 397. 



" Geebung." A very dark gum has been observed (12th June, 

 1888) on this species. It seemed to resemble that of Grevillea 

 ■Striata J but w^as not sufficiently abundant to collect. 



Stenocarpus salignus, R. Br., B. FL, v. 539. 



" Beef-wood," " Silky Oak," kc. Small quantities of gum have 

 been seen on bruised trees of this species several times. The 

 author looks upon gum as being usually a pathological product, 

 and it is therefore most likely to be found on sickly and injured 

 trees. 



Xylomelum pyriforme, Knight, B. FL, v. 408. 



This is the well-known " Native Pear " of New South Wales. 

 I am not aware that the finding of gum on this tree has been 

 previously announced. 



I found a small quantity of a yellowish-brown gum, tough, and 

 of dull appearance, on a sapling which was six inches in diameter, 

 but which had been cut down, leaving four feet of stump, from 

 which there was a free growth of new leaves — a testimony also 

 that the gum had exuded some time. 



It swells up largely in cold water, and then disintegrates, 

 forming masses of a nearly colourless jelly. I have analysed it 

 with the following result : — 



Arabin... ... ... trace 



Pararabin ... ... 79*56 



Moisture ... ... 17*35 



Ash -55 



It may, therefore, be considered to consist solely of pararabin. 



