234 



H. G. SMITH, 



bark was slightly swollen, and had the general appearance 

 of sheet rubber without its elasticity. 



Numerous specimens of M. uncinata from various Aus- 

 tralian localities are in the Museum herbarium, and they 

 all have this thin outer bark on the stem and twigs, which 

 ignited readily and gave a similar odour in each case. This 

 peculiarity is thus a constant feature with this species of 

 Melaleuca throughout the whole range of its distribution. 



Although nearly one-fourth of this thin outer bark con- 

 sists of resin, yet a natural exudation of the resin has not 

 been observed, although one might expect such to occur 

 under abnormal conditions. 



The resin, after extracting from the finely powdered 

 bark with boiling alcohol and evaporating to dryness on the 

 water bath, was of an orange-brown colour, semi-trans- 

 parent, in thin pieces, very brittle, and easily powdered 

 between the fingers. In general appearance it somewhat 

 resembles ordinary shellac, but is less transparent and 

 more brittle. The specific gravity was 1*135 at 15° O. 



The resin was almost entirely soluble in alcohol, more so 

 in ether-alcohol and readily in acetone. It was only 

 slightly soluble in chloroform, the portion going into solution 

 being principally the neutral bodies and not the acid resin. 

 Benzene acted similarly to chloroform. Turpentine had 

 little action even on continued boiling. The resin was only 

 partly soluble in ethyl-acetate. 



The resin was practically soluble in hot glacial acetic 

 acid, remaining in solution when cold. On slow evaporation 

 microscopic crystals were formed in quantity, the whole 

 mass being more or less crystalline. 



The resin was only slightly dissolved on boiling in a. 

 solution of borax. 



