PRESIDENTIAL ADDRESS. 39 
are comparatively small in this group also. This fact, 
taken together with the small ash yield, renders the timbers 
of these species of little use for the production of potassium 
carbonate. <A greater amount of potassium could, of 
course, be obtained from the leaves of the more pronounced 
alkali-bearing species. 
The data given in these tables suggest somewhat strongly 
the direction of chemical influences governing the natural 
distribution of the several species of the groups of this most 
extensive genus. | 
Table No. II. 
Percen- | Percen- | Percen- 
tage in | tage in | tage in 
Ash, Ash. Ash. 
(P2035) (CaO) (MgO) 
po eag® sce. hemiphloia (wood) ...| 0°49 | 52°42) 1°40 
EL. albens (wood) ... Orde D072,0) tne Siies 
ee eacks” HE. siderophloia (wood) ...| 1°58 | 31:14] 6°55 
E. paniculata (wood) an ele GSAS: bon F220 
“Ashes ” { #. Delegatensis ee ...| 1°50 | 19°50 | 23-42 
| £. regnans (wood) .. al Ion beat e020: 
| #. pilularis, Ashfield (wood) 18°9 6°65 
1-92 
“Blackbute” do. mixed species (wood)| 1°80 | 14:2 6:10 
do. No. 1 tree (leaves) | 1°49 / 11:0 | 13-60— 
»( LH. macrorrhyncha (wood) | 1:61 | 10°13} 7°79 
ee 1 ganiaiice (wood). | 1-41, | 11-23 | 96-30. 
The time at my disposal only permitted the investigation 
of a limited number of species of EHucalypts, in fact it was 
only possible to touch the fringe of this important question 
concerning the mineral food requirements of the members 
of the several groups of this great genus, but sufficient has 
been done to demonstrate somewhat clearly that great 
advantage to Australia would be likely to accrue from 
more complete and extended studies on this group of trees. 
