PRESIDENTIAL ADDRESS. 35 
possible upon which these trees can continue to live and 
thrive. What necessary function the inorganic matter 
plays in the development of cellulose, as well as in other 
natural colloidal substances is not known, but that it is 
incidental to the vital processes of the plant can hardly be 
doubted. More complete and extended studies in colloidal 
chemistry, and a knowledge of the influences exerted by 
the enzymes, or organic catalysts, when considered with 
those of inorganic origin, would, no doubt, do much to solve 
many of the problems so closely connected with the . 
phenomena of vegetable life. 
The table (No. 1) gives the percentages and parts of ash 
and manganese in the portions of the trees treated. The 
species include representatives of the several groups into 
which the genus Hucalyptus naturally divides itself. The 
results show that the inorganic portions of the groups of 
trees are somewhat constant in character, and agree closely 
jo this respect with the organic chemical constituents of 
the various species of Kucalyptus. Perhaps it is for this 
reason that the organic chemical characters are of such a 
constant nature. 
It will be observed that the similarity existing between 
the members of the “‘Ironbark”’’ group, for instance, and 
between those of the ‘‘Boxes”’ is not peculiar, and that 
the two “‘Stringybarks,”’ E. macrorrhyncha and H. eugeni- 
oides also show agreeing results, while EH. obliqua is more 
in conformity with H. Delegatensis and EH. regnans, this 
being in agreement with the botanical evidence. H. 
botryoides is also shown to differ somewhat from E. saligna, 
while the two “‘Peppermints”’ EH. amygdalina and E. dives 
are in accord. The figures also indicate that of the ‘‘Iron- 
barks,”’ E. erebra would prefer to grow on land less rich in 
available basic mineral food material than would appear to 
be necessary for some of the other members of this group. 
