156 TWO NEW SPECIES OF ACACIA FROM N.S.W., 



long, attenuated, moniliform pod, the elongated seed, and the 

 short filiform funicle. It is further distinguished from A. penni- 

 nervis by its shrubby growth, being never recorded as a tree; by 

 its remarkably flat branchlets ; by the edges of the phyllodes 

 being less nerve-like, and also by its sepals and petals. 



In botanical sequence its place is between A. ])e)ininervis, 

 Sieb., and A. retinoides, Schl. 



It is one of the few Acacias exuding a soluble gum, and I am 

 indebted to Mr. H. G. Smith, of the Technological Museum, for 

 the following note on the chemistry of its gum : — 



The gum occurring on this species is principally in globular 

 masses of various sizes up to that of a pigeon's egg. Portions of 

 the gum are quite transparent. The colour is mostly of a pale 

 amber, although some portions are of a darkish brown. The 

 gum breaks readily with a bright conchoidal fracture, and when 

 coarsely powdered much resembles in appearance the better class 

 of gums belonging to the arabin group. It is entirely soluble in 

 two or three parts of cold water, with the exception of a small 

 quantity of accidental impurity (bark, l*cc.). The mucilage 

 formed is of fair viscosity, and strongly adhesive. The aqueous 

 solution is acid to test paper, and is rather dark in colour ; 

 alumina, however, clears it sufiiciently to allow the determination 

 of its optical properties to be made; it was found to be lajvo- 

 rotatory like the better class gums. When boiled with dilute 

 sulphuric acid the solution becomes dextro-rotatory, most probably 

 from the formation of Arabinose. Although the present specimen 

 was found to have well-defined optical properties, j^et it is often 

 found that the Australian gums are optically inactive. 



No precipitate was formed on adding neutral lead acetate, nor 

 was there any alteration on the addition of ferric chloride, except 

 a slight darkening of the solution. On heating with caustic soda 

 the solution becomes yellowish to brownish. 



The water present was found to be 13-35 per cent. The ash 

 is small in quantity, being only "88 per cent ; this consists of the 

 usual bases found in connection with arable acid in most gums. 



