SECTION B. 
CHEMISTRY. 
PRESIDENTIAL ADDRESS. 
By Prorsessor A. Mica Smita, Ballarat, Victoria. 
THE STUDY OF THE CHEMISTRY OF THE AIR 
_AND WHITHER IT HAS LED. 
SincE the last meeting of our Association, two great cen- 
turies have met and parted: the one. full of honours and a 
hundred crowded years of magnificent scientific achievement, 
takes its place with its predecessors; the other bears.us with 
it into a future of the most extravagant promise. 
Many of the scientific discoveries in which the last century 
is so rich trace their springs—sometimes tiny enough—to 
the one or two preceding centuries, if not to still earlier 
times, and this is conspicuously the case with at least some 
of the discoveries concerning which I have the honour of 
addressing you to-day. 
The commonest things are often in some respects the most 
important things. They are important because they are 
common, and common because they are important. Atmo- 
spheric air is one of these. 
Karty FANCIES. 
We can easily sympathise with our early ancestors in their 
attempt to understand the mystery of the atmosphere. The 
air is forced upon our attention; we cannot escape from it 
with life; a vast ghostly presence, enveloping our earth and 
ourselves in its embrace, interpenetrating all things, and, 
withal, endowed with human moods. Sometimes, for a 
brief space, still ; now gently fanning our cheek, now moving 
in fitful gusts, now angered into a storm, now possessed with 
the fury of an enraged demon, uprooting trees and laying 
waste the country, scooping up and flinging aloft acres of 
soil, or many a ton of sea with its living inhabitants, and, 
when it has spent its fury and exhausted itself with slaughter, 
falling again to temporary calm. Now it blows, hot, now 
cold; now dry, now moist; now precipitating out of its sub- 
stance rain or hail, or dew or snow—surely the very embodi- 
