24 HENRY G. SMITH. 



investigated for the purpose of this inquiry : — " Grey 

 Mallee " (Eucalyptus Morrisi), "Water Mallee" (E. oleosa), 

 "Bull Mallee" (E. dumosa), "Green Mallee" (E. viridis), 

 "Blue Mallee " (E. polybractea), " Mallee" (E. Behriana), 

 "Mallee " (E. gracilis), "Mallee" (E. stricta). The vari- 

 ous stages of the bark of the tall smooth barked tree, 

 growing on the Blue Mountains, Eucalyptus oreades, were 

 also examined. 



When the powdered bark of E. salmonophloia was heated 

 with water, white crystals separated in some quantity, of 

 which a considerable amount floated on the top of the 

 water. When boiled for some time the bark debris pre- 

 cipitated, and the crystals could then be removed with a 

 spatula. They were collected in as pure a condition as 

 possible, well washed and dried on a porous slab. Chemical 

 determination showed them to consist of calcium oxalate. 

 Under the microscope they were seen to be well defined 

 monoclinic crystals, consisting principally of stout micro- 

 scopic prisms. Many of the crystals were twinned, the 

 twinning plane being, apparently, parallel to the basal 

 plane, thus giving the twin a geniculate form. This form 

 of twinning was very apparent with some species, as for 

 instance, jE. polybractea. The crystals polarised exceed- 

 ingly well in bright colours. The bark of E. salubris gave 

 an abundance of crystals identical in every respect with 

 those obtained from E. salmonophloia, and the few crystals 

 from E. redunca and from E. occidentalis were also 

 identical. From all the barks of the New South Wales 

 Mallees the same characteristic monoclinic crystals were 

 obtained, and in form and appearance they were identical 

 with those from the West Australian barks, with the excep- 

 tions that the crystals from E. gracilis were generally 

 shorter and stouter, and those from E. polybractea were 

 longer ; in other respects they were the same. This form 



