642 
popular imagination. The isolated events to which 
variation is due are evidently changes in the germinal 
tissues, probably in the manner in which they divide. 
It is likely that the occurrence of these variations is 
wholly irregular, and as to their causation we are 
absolutely without surmise or even plausible specula- 
tion. Distinct types once arisen, no doubt a pro- 
fusion of the forms called species have been derived 
from them by simple crossing and subsequent recom- 
bination. New species may be now in course of 
creation by this means, but the limits of the process 
are obviously narrow. On the other hand, we see 
no changes in progress around us in the contemporary 
world w hich we can imagine likely to culminate in the 
evolution of forms distinct in the larger sense. By 
intercrossing dogs, jackals, and wolves new forms of 
these tvpes can be made, some of which may be 
species, but I see no reason to think that from such 
material a fox could be bred in indefinite time, or that 
dogs could be bred from foxes. 
Whether science will hereafter discover that certain 
groups can by peculiarities in their genetic physiology 
be declared to have a prerogative “quality justifying 
their recognition as species in the old sense, and that 
the differences of others are of such a subordinate 
degree that they may in contrast be termed varieties, 
further genetic research alone can show. I myself 
anticipate that such a discovery will be made, but I 
cannot defend the opinion with positive conviction. 
Somewhat reluctantly, and rather from a sense of 
duty, I have devoted most of this address to the evolu- 
tionary aspects of genetic research. We cannot keep 
these things out of our heads, though somtimes we 
wish we could. The outcome, as you will have seen, 
is negative, destroying much that till lately passed 
for gospel. Destruction may be useful, but it is a 
low kind of work. We are just about where Boyle 
was in the seventeenth century. We can dispose of 
alchemy, but we cannot make more than a quasi- 
chemistry. We are awaiting our Priestley and our 
Mendeléeff. In truth it is not these wider aspects of 
genetics that are at present our chief concern. They 
will come in their time. The great advances of 
science are made like those of evolution, not by im- 
perceptible mass-improvement, but by the sporadic 
birth of penetrative genius. The journeymen follow 
after him, widening and clearing up, as we are doing 
along the track that Mendel found. 
SECTION A. 
MATHEMATICS AND PHYSICS. 
Opreninc ApprEssS BY Pror. F. T. Trouton, M.A., 
Sc.D., F.R.S., PRESIDENT OF THE SECTION. 
WE have lost since the last meeting of the Section 
several distinguished members who have in the past 
added so much to the usefulness of our discussions. 
These include Sir Robert Ball, who was one of our 
oldest attendants, and was president of the section at 
the Manchester meeting in 1886; Prof. Poynting, who 
was president of the section at Dover in 1899; and 
Sir David Gill, who was president of the Association 
at Leicester in 1907. 
It seems appropriate at this meeting in the City of 
Melbourne to mention one who passed away from his 
scientific labours somewhat previous to the last meet- 
ing. I allude to W. Sutherland of this city, whose 
writings have thrown so much light on molecular 
physics and whose scientific perspicacity was only 
equalled by his modesty. 
This meeting of the British Association will be a 
memorable one as being indicative, as it were, of the 
scientific coming of age of Australia. Not that the 
NO. 2338, VOL. 93] 
NALORE 
' 
[AucusT 20, 
IQI4 
maturity of Australian science was unknown to those 
best able to judge, indeed the fact could not but be 
known abroad, for in England alone there are many 
workers in science hailing from Australia and New 
Zealand, who have enhanced science with their in- 
vestigations and who hold many important scientific 
posts in that country. In short, one finds it best 
nowadays to ask of any young investigator if he 
comes from the Antipodes. 
This speaks well for the universities and_ their 
staffs, who have so successfully set the example of 
scientific investigation to their pupils. 
Radio-activity and kindred phenomena seem to have 
attracted them most of late years, and it would per- 
haps have been appropriate to have shortly reviewed 
in this address our knowledge in these subjects, to 
which the sons of Australasia have so largely con- 
tributed. 
Twenty-five years ago FitzGerald and others were 
speculating on the possibility of unlocking and utilising 
the internal energy of the atom. Then came the 
epoch-making discovery of Becquerel, to be followed 
by the brilliant work of Rutherford and others show- 
ing us that no key was required to unlock this energy, 
the door lay open. 
We have still facing us the analogous case of a 
hitherto untapped source of energy arising from our 
motion through the ether. All attempts, it is true, to 
realise this have failed, but nevertheless he would be 
a brave prophet who would deny the possibility of 
tapping this energy despite the ingenious theories of 
relativity which have been put forward to explain 
matters away. ‘There is no doubt but that up to the 
present nothing hopeful has been accomplished to- 
wards reaching this energy and there are grave 
difficulties in the way; but ‘‘ Relativity’ is, as it were, 
merely trying to remove the lion in the path by laying 
down the general proposition that the existence of 
lions is an impossibility. The readiness with which 
the fundamental hypotheses of “ Relativity’’ were 
accepted by many is characteristic of present-day 
physics, or perhaps more correctly speaking is an 
exaggerated example of it. 
Such an acceptance as this could hardly be thought 
of as taking place half-a-century ago when a purely 
dynamical basis was expected for the full explanation 
of all phenomena, and when facts were only held to 
be completely understood if amenable to such treat- 
ment; while, if not so, they were put temporarily 
into a kind of suspense account waiting the time 
when the phenomenon would succumb to treatment 
based on dynamics. 
Many things, perhaps not the least among them 
radio-activity, have conspired to change all this and 
to produce an attitude of mind prepared to be content 
with a much less rigid basis than would have been 
required by the natural philosophers of a past genera- 
tion. These were the sturdy Protestants of science, 
to use an analogy, while we of the present day are 
much more catholic in our scientific beliefs, and in 
fact it would seem that nowadays to be used to any- 
thing is synonymous with understanding it. 
Leaving, however, these interesting questions, I 
will confine my remarks to a rather neglected corner 
of physics, namely to the phenomena of absorption 
and adsorption of solutions. The term adsorption 
was introduced to distinguish between absorption 
which takes place throughout the mass of the absorb- 
ing material and those cases in which it takes place 
only over its surface. If, for instance, glass, pow- 
dered so as to provide a large surface, is introduced 
into a solution of a salt in water, we have in general 
some of the salt leaving the body of the solution and 
adhering in one form or other to the surface of the 
| 
