108 : “HENRY G. SMITH. 
probable that that deposit was obtained from the timber 
of the ‘‘Silky Oak’? Orites excelsa, and not from that of 
Grevillea robusta. This mistake might easily occur as 
the same vernacular name is applied to both trees. 
My colleague Mr. R. T. Baker, F.L.s., (to whom I am 
much indebted for botanical information in preparing this 
paper) assures me that the discrimination between the 
timbers of these two species is not easy, the resemblance 
between them being often most marked, and that it is 
necessary to procure further botanical evidence before the 
identity of the timber can be placed beyond dispute. The 
results of the present investigation may, perhaps, supply a 
simple method of diagnosis, if at any time such is needed. 
It can readily be understood how easily these timbers might 
be mistaken for each other at the saw mills, and thus sup- 
plied indiscriminately. 
The occurrence of the deposit of aluminium succinate 
was, at the time of its first discovery, thought to be of 
some physiological importance, and efforts were made to 
procure, if possible, the sap from the living trees of G. 
robusta, so that the constituents might be determined. A 
small quantity of this sap was procured for me later by 
Mr. W. P. Pope, the Forester in the Lismore District ; 
from this I made as complete an analysis as possible, the 
results of which were submitted to this Society in a paper 
read, October 1896. The presence of free butyric acid was 
determined in the sap, so that the origin of the succinic 
acid was thought to be explained, it being derived from 
the butyric acid of the sap by natural oxidation. The 
origin of the aluminium was not so evident, because the 
investigation showed that element to be absent in the sap, 
and the ash of a sample of the wood obtained from an 
undoubted tree of G. robusta was quite free from alumina. 
There the matter remained until quite recently, when the 
