32 ON SOME N S.W. TAN-SUBSTANCES. 



lias approximately the same geographical range as A. 

 decurrens. These two species are so closely allied that 

 it is only within the last three or four years that Baron 

 Mueller has conceded specific rank to A. dealbata. This 

 similarity does not extend to the barks, in the learned 

 Baron's opinion, for he says, (Select Extra-tropical 

 Plants,) " The bark of this variety (dealbata) is much 

 thinner and greatly inferior to the Black Wattle (A. 

 decurrens, and var. mollissima presumably) in quality, 

 yielding only about half the quantity of tanning 

 principle." This can only allude to the higher percentages 

 of tannin obtained by the Baron for A. decurrens, for as 

 the result of perhaps 30 analyses of the barks of A. 

 dealbata and A. decurrens, made by me, I find not such 

 a great disparity between them. The matter can scarcely 

 be settled until the barks of two trees of the two species 

 similar in every respect, and treated in precisely the 

 same manner shall have been analysed. 



It may be convenient to give the following comparison 

 of the barks (as far as they are represented in the 

 Technological Museum), since their botanical affinities 

 are so close : 



A. decurrens A. dealbata. 



1. Smooth, or with very slight 1. Furrowed, flaky, and rug- 



longitudinal flutings. ged looking. 



2. Thickness about half that 



of A. dealbata. 



3. Yields a purplish extract to 



water, much more intense 



than that of J., decurrens. 



The residue is exceedingly 



like spent logwood in 



appearance. 



These particulars must of course be compared in connection 



with the information given in this paper in regard to the tree 



whence the bark of A. dealbata was obtained, and in the paper 



for June in regard to A. decurrens. 



Vernacular Name — " Silver Wattle." 



Locality whence this particular specimen was obtained — 



Quiedong, near Bombala, N.S.W. 

 Part of the Tree Examined — -Bark. 

 Particulars of the trees whence it was obtained — Height 20 



to 30 feet, diameter 12 to 18 inches. 

 Collected 1st March, 1887. Analysed 5th to 23rd July, 1887. 



A very rugged bark, both from longitudinal and transverse 

 fissures. Colour dark grey to black. Inner bark tough and of a 

 reddish-brown colour. Average thickness of bark barely \ inch. 

 Yields a dark reddish-brown powder. 



