ON SOME N.S W. TAN-SUBSTANCE3. 93 



Extract. — Soluble in water at 100° C. to the extent of 29*86 

 per cent. 



Catechu-tannic acid — 21*22 per cent. 



28. Acacia decurrens, Willd* 



Vernacular Name — " Green Wattle." 



Locality whence this particular specimen was obtained — 



Ryde, Parramatta River, Sydney, N.S.W. 

 Geological Formation — Sandstone. 

 Part of the Tree Examined — Bark. 

 Particulars of the tree whence it was obtained — Height 15 feet, 



diameter 3 to 4 inches. 

 Collected 29th May, 1887. Analysed 5th to 18th July, 1887. 



Extract. — Dissolves in water at 100° 0. to the extent of 48'74 

 per cent. 



In the report of the Board of Enquiry on Wattle Bark, appointed 

 by the Victorian Government, (Melbourne, 1878) the following 

 percentages of extract are given for A. decurrens bark grown in 

 different localities : — 29, 34, 40 and 45. 



Catechu-tannic acid — 



The bark now under examination yields 32*33 per cent., and is 

 more than ordinarily uniform in quality. 



Notes on A. decurrens. — The variety growing about Sydney is 

 A. decurrens var. normalis, Benth. The Victorian and Tasmanian 

 variety is A. decurrens var. mollis, Lindl., or mollissima, and 

 corresponds to A. mollissima, Willd., vide B. Fl. ii., 415. In the 

 Flora Austrcdiensis these varieties (and others which occur) are 

 merged in the one species A. decurrens. Baron Mueller does not 

 alter this arrangement in his Census. The Baron experimented 

 on the bark of the mollissima variety, (" Select Extra-tropical 

 Plants," N.S.W. Edition, page 3) and obtained " from 30 to 54 

 per cent, of tannin in bark artificially dried." In my experiments 

 the variety normalis has been used, but the two varieties are so 

 closely allied botanically that it is not likely that any great 

 difference will be found to exist in the barks. In the Catalogue 

 of Queensland Woods at the Colonial and Indian Exhibition the 

 percentage of tannin in a (presumably) Queensland grown bark of 

 A. decurrens is given at 15*08, but no further particulars are 

 given. But it is a well-known fact that the tannin in this species 

 diminishes as the climate grows warmer and drier. 



* See p. 33, Proc. E. S. (N.S.W.) 1887, for particulars of natural order, 

 locality &c, of this species. The bark now experimented upon differs 

 from the former specimen in being blacker on the outside, of a lighter 

 colour inside, and in being slightly thicker. 



