PRESIDENTIAL ADDRESS, 27 
been detected as occurring in plants, as well as minute 
quantities of such common elements as copper, zinc, barium, 
etc. In one species of Hucalyptus copper was detected; 
this was found in the ash of the timber of the ‘‘ Ironbark ’” 
EK. sideroxylon, growing at Condobolin, and was separated 
in the metallic form. The general map published by the 
Mines Department does not include Condobolin in the 
cupriferous districts of New South Wales, but there is now 
no doubt but that copper does occur in that district as 
indicated by this Kucalyptus.* 
The repeated occurrence of manganese in the ash of the 
wood of the Australian Callitris led to an extended study 
as to position, and it was found that this element occurs 
in all parts of the plant; seeds, seed cases, leaves, bark, as 
well as in the timber, but alwaysin minute proportion. As 
the manganese is found in the ashes of all the species of 
Callitris it is reasonable to suppose that its presence is 
essential to the satisfactory growth of these trees, and is 
perhaps, as important in this connection as either potassium 
or phosphorus. 
These results with the Callitris led to further inquiry in 
the same direction with the other extensive Australian 
genus—Hucalyptus. So far as investigation has proceeded 
it is shown that manganese is also a constant constituent 
in the ash of all the species of this genus, and further, that. 
there is a remarkable uniformity between the percentage 
amounts of manganese in the ash of the several species 
belonging to the same group, and that this is irrespective 
of the location where the trees grow, even if these are 
hundreds of miles apart. It appears, therefore, that the 
uniformity in the amounts of this necessary food material, 
taken in conjunction, perhaps, with other ash constituents, 
have been granted near Condobolin to the north, for working copper, etc., 
indicated in Map Sheet 9 of the Mining Districts of New South Wales. 
