ON SOME N.S.W. TAN- SUBSTANCES. 185 



gardeners in Hobart sustained while in the act of removing one of 

 these trees. 



Rhus glabrum. — The bark is considered a febrifuge, and is also 

 employed as a mordant for red colours. 



32. Leaves. — The follow description, (so far as pertains to 

 the leaves) is taken from the " Flora Australiensis ": — "A tree of 

 70 to 80 feet,* quite glabrous except little tufts of hairs along the 

 midrib of the leaflets underneath. Leaves pinnate, the common 

 petiole terete ; leaflets usually 7 or 9, oblong, obtusely acuminate, 

 mostly 2 to 2-J inches long, entire, shortly petiolulate, the pinnate 

 veins prominent underneath." I would supplement this description, 

 at least as far as the particular tree from which my specimens 

 were taken, as follows : — Leaves impari-pinnate, with usually five 

 pairs of leaflets, which frequently are not strictly opposite, and 

 therefore may perhaps better be described as alternately pinnate. 

 Leaflets usually 2 J to 3 inches long. 



These leaves were ground moderately fine in a small coffee mill. 

 In the case of ordinary Sumach the desideratum is to produce a 

 very fine powder, which of course facilitates the preparation of 

 extract, and also makes the Sumach more homogeneous. 



Extract. — They yield 32-2 per cent, to water at 100° C. Colour 

 of solution yellowish-brown (with an olive shade), not to be 

 distinguished in colour from that yielded by ordinary sumach. It 

 remains clear on filtering. Colour of moist residue dark olive- 

 brown. 



Tannic acidj — 16*91 per cent. An exceedingly satisfactory 

 result, especially when it is borne in mind that sumach-yielding 

 trees are never stripped in winter. Moreover this was by no 

 means a young and perfectly vigorous tree, for its leaves were 

 rather discoloured, and many of the branchl'ets infested with a 

 coccus. This tree is entitled at least to rank with the North 

 American Sumachs, and it now remains with some enterprising 

 agriculturalist to prove whether or not it may be a formidable 

 rival to those of Southern Europe. 



For purpose of comparison, I have analysed a sample of ordinary 

 commercial Sumach, as purchased in Sydney (August 1887) and 

 probably obtained from R. Coriaria. I find that it contains 24*05 

 per cent, of Tannic acid, and Extract 50*36 percent., the solution 

 being of a yellowish-brown with shade of olive, and the moist 

 residue olive-brown. The filtrate from this sumach deposited a 

 dark flocculent precipitate on cooling ; the leaves of Rhus 



* It will be observed that R. rhoclanthema grows to a far larger size than 

 the species of Rhus at present cultivated for Sumach, 

 f Usually considered as iientical with gallo-tannic acid. 



M— October 5, 1887. 



