HARRY BOr,US, D.SC, F.L.S. 79 



1896. Contributions to the Flora of South Africa- Journal of Botany. 



vol. xxxiv. 

 1896- Iconcs Orchidcantui .Uistro-AfricanaruDi cxira-tropicaniiii. vol- i. 



Part II. (with tifty plates). 

 1903. A List of the Flowering Plants and Ferns of the Cape Peninsula, 

 with notes on some of the critical species (with A. H. vVollev 

 Dod). Transactions South African Philosophical Society- 

 1905. Sketch of the Floral Regions of South Africa. Science in South 

 Africa ; A handbook and review- 

 The Genus Erica (in part with F- Gutlirie). Flora Capensis- 



vol. iv. 

 Contributions to the South African Flora Transactions South 



African Philosophical Society, vol. xvi. 

 Contributions to the African Flora. Transactions South African 



Philosophical Society, vol- xvi- 

 Contributions to the African Flora. Transactions South African 



Philosophical Society, vol. xviii. 

 Contributions to the African Flora (with L. Kensit). Trans- 

 actions Royal Society of South Africa, vol. i- 

 A new Cissus from the Transvaal. Journal of Botany, vol. xlvii. 

 Iconcs Orchidearum Aiistro-Africanarum, extra-tropicarum, vol- ii, 

 (100 plates). 



[Unpublished — hones Orchidearum Austro-Africanarum, extra-tropi- 

 carum, vol- iii (circa 40 plates)-] 



1905 



1905 



1906 



1907 



1909 



1909 

 1911 



Utilis.'Vtion- of Wattle Bark. — In the latest Bulletin of 

 the Imperial Institute (Vol. 9, No. 2) special attention is drawn 

 to the value of wattle bark for tanning, and to the increasing 

 production of this material in Southern Africa. Emphasis is 

 also laid on its relative cheapness. Recently a nutniber of analyses 

 of black wattle barks obtained from Natal, the Cape Province, 

 the East Africa Protectorate, and Australia were made in the 

 laboratories of the Imperial Institute, and the following per- 

 centages of tannin were found: Natal, 35.2 to 39.8; Cape, 40.1 

 to 44.1 ; East Africa, 36.7 to 42.1 ; Australia, 38.3. All these 

 barks are rich in tannin, and they posses the additional advan- 

 tage of containing only small proportions of non-tannin extrac- 

 tive matter. The tannin in wattle bark is. moreover, easily 

 extracted, and the liquors prepared from the bark lose com- 

 paratively little in strength when kept. The cjuality of the bark 

 on the market is stated to show but little variation, and owing 

 to increasing production there is no danger of a failure in supply. 

 For the production of heavy leathers Paessler considers wattle 

 bark superior to all other tanning materials except Quebracho 

 wood. 



