ABSTRACT OF PROCEEDINGS. IX. 



1900. That this Society desires to convey its sympathy 

 with the relatives of their colleague." 



THE FOLLOWING PAPERS WERE READ : 



1. " On the occurrence of Calcium oxalate in the barks of 

 the Eucalypts," by Henry G. Smith, f.c.s., Assistant 

 Curator, Technological Museum, Sydney. 



The author announces the presence, in large quantities, 

 of calcium oxalate in the barks of several species of 

 Eucalyptus. It is similar in form and appearance in all 

 species, being well defined monoclinic crystals in stout 

 microscopic prisms, averaging 0*0174 mm. in length, and 

 0*0077 mm. in breadth and containing one molecule of water. 

 A peculiarity of these is the tendency to form twins 

 geniculate in appearance ; twinned forms being pronounced 

 in some species. From botanical and chemical evidence it 

 is assumed that Eucalyptus salmonophloia of West Australia 

 and E. oleosa of New South Wales belong to the same 

 species, and that the latter tree, which most often occurs 

 as a " Mallee," is only the degenerate stage of the former. 

 The theory is advanced that some of the " mallees," or 

 shrubby Eucalypts, have been formed through the poisoning 

 effect of the excess of oxalic acid, acting for a long time 

 upon species which originally grew as large trees. The 

 tannins in those Eucalyptus barks containing a large 

 amount of calcium oxalate are of very good quality, light 

 in colour, astringent, easily soluble, and should make leather 

 of good quality. On evaporating the extract to dryness on 

 the water bath but little darkening takes place, and the 

 product is still readily soluble. This class of Eucalyptus 

 barks should, therefore, make excellent tanning extracts. 

 From the bark residue the calcium oxalate should be profit- 

 ably extracted, and the oxalic acid obtained cheaply from 

 this, practically as a by-product. The air dried bark of 

 Eucalyptus salubris, the "Gimlet "of West Australia, gives 



