114 HENRY 'G. SMITH, 
The conditions under which the aluminium has been 
assimilated by this species must be either favourable or. 
unfavourable, but it can hardly be the latter when the trees 
from the various localities are considered. A photograph 
of the log of the Queensland specimen, as received at 
the Museum, is here reproduced, and it will be seen 
that the section of the tree is about three feet in diameter. 
This timber, as “Silky Oak’’ was procured from Queens- 
land by the Colonial Sugar Company for the manfacture of 
casks. It is to the kindness of Mr. T. Steel, F.c.s., to Mr. 
T. U. Walton, Bsc, and to the General Manager of the 
Company, that the Museum has come into possession of 
this material. 
From the photograph it will be seen that the cavity in 
the tree (which is not due to decay but to abnormal growth) 
was completely filled with the aluminium succinate, but it 
had been removed from the larger end before the photo- 
graph wastaken. A considerable quantity of the succinate 
was obtained from the cavity, so that it has been possible 
to elucidate most of the problems suggested by the occur- 
rence of this deposit. (For photograph see Plate 4.) 
It seems reasonable to expect that aluminium, probably 
as a butyrate, or as an aluminate of potash, will be found 
in the sap of Orites excelsa, because free butyric acid was 
the only volatile acid found in the deposit, and alumina as 
potassium aluminate was present in the soluble portion of 
the ash when this was boiled with water. When the log 
was cut it was still unseasoned, and as it dried, microscopic 
masses (probably the aluminium succinate) accumulated at 
the ends of some of the cells, indicating that the salts were 
originally in solution in the sap. 
_ Butyric acid appears to be a constant constituent in the 
sap of this class of Proteaceous trees, and I had previously 
found it in the sap of Grevillea robusta. The question 
