OCCURRENCE OF ALUMINIUM SUCCINATE IN TREES. 107 
ALUMINIUM tHE CHIEF INORGANIC ELEMZNT In 
A PROTEACEOUS TREH, AnD THE OCCURRENCE 
oF ALUMINIUM SUCCINATE 1n TREES 
OF THIS SPECIES. 
By HENRY .G. SMITH, F.C.S., 
Assistant Curator, Technological Museum, Sydney. 
[With Plate IV.] 
[Read before the Royal Society of N. 8. Wales, July 1, 1903. ] 
Orites excelsa, R. Br., a tree belonging to the Natural 
Order Proteacee, occurs somewhat plentifully in northern 
New South Wales and Queensland. It is often a tall tree 
with a diameter up to three feet. It has prettily figured 
timber, the medullary rays being very pronounced and 
extending from the centre of the tree to the bark. Itisa 
useful wood for the cabinet maker. It is one of the many 
trees known generally in Australia as “‘ Silky Oaks.’’ It 
is a timber of comparatively low specific gravity and is 
usually light in colour. It may now be said that scientifi- 
cally its interest lies in the fact that it utilises the element 
aluminium in large quantities in its construction, and so 
differs from all other flowering plants, so far as these have 
been investigated. Aluminium appears to be necessary to 
the growth of this tree, as in the ash from the four speci- 
mens investigated, large quantities of alumina were found. 
Occasionally the amount taken up is abnormal, as in the 
Queensland specimen, and when this occurs the excess is 
deposited in cavities as a basic aluminium succinate. 
In November 1895 a paper was read before this Society 
by Mr. J. H. Maiden, F.L.s. and myself, on a natural deposit 
of aluminium succinate found occurring in the timber of a 
“Silky Oak”’ which at that time was thought to be Grevillea 
robusta... From the evidence here produced it is most 
