OCCURRENCE OF ALUMINIUM SUCCINATE IN TREES. 113 
ious growth, the principal inorganic element of which is 
aluminium. This element occurs in this tree (Orites excelsa) 
as, apparently, a necessary inorganic constituent to its 
growth, and it also occurs as deposits of a basic aluminium 
succinate, the latter being found filling the cavities and 
natural fissures of the wood. The deposition of aluminium 
succinate in living trees, in quantity, is exceedingly inter- 
esting, because the salt is composed of an acid rarely 
occurring in quantity in plant life, andin combination with 
a base which as shown above is scarcely ever present. 
The deposit, however, is of even less physiological interest 
than the tree itself from which it is obtained. The rarity 
of occurrence of even traces of aluminium in the Phanero- 
gams makes this discovery of more than passing interest. 
It does not follow, perhaps, that the detection of this or any 
other element in the ash of plants is a priori evidence of 
the necessity of this element in the building up of any par- 
ticular plant, this evidence being usually obtained by direct 
experiment; but from our present knowledge it can hardly 
be denied that aluminium is necessary to the construction 
of Orites excelsa, because of the enormous amount of that 
element often found in the ash, and the formation of the 
aluminium succinate is probably Nature’s method for get- 
ting rid of an excess. 
In the Queensland sample the vascular portion can 
occasionally be stripped from the medullary rays in layers, 
forming a cellular open network of fibre, and this when 
carefully ignited leaves a skeleton of ash resembling in 
shape the portion taken, and consisting almost entirely of 
alumina. So pronounced is it that if the skeleton of ash 
be moistened with a solution of cobalt nitrate and ignited 
before the blowpipe, the characteristic blue colour is readily 
obtained, the other salts being too small in amount to inter- 
fere with the reaction. The ash of this specimen was also 
infusible or fusible with great difficulty. 
