At first he turned his attention to geology and conchology. publishing, in 1866, an appendix to S. P. Woodward's "Manual of Mollusca," and, in 1871, a "Rudimentary Treatise on Geology." In 1876 he published, in conjunction with Mr. J. F. Blake, a book on the "Lias of Yorkshire." On his appointment to the Chair in the Adelaide University, he at once, with great zeal, threw himself into the study of the geology and paleontology of South Australia, making extensive travels over the country. He now added botany to his other accomplishments, and published a "Handbook to the Flora of South Australia."

He was President of Section D of this Association at its first meeting in Sydney in 1887, taking for the subject of his address the geographical distribution of the plants of Australia and its relation to the geological history of the continent. When we met at Adelaide, in 1893, he was chosen President, and gave us a very complete account of the progress of geological discovery in Australia. And, at the Melbourne meeting, in 1900, as President of Section C. he made a vigorous attack on the doctrine of homotaxy.

THE ASSOCIATION.

During the ten years which have passed since our previous meeting in Hobart, the Association has grown greatly in strength and influence through the good work it has done for the advancement of science in the Southern Hemisphere, and I think that our Permanent Secretary, who was the founder of the Association, ought to be proud of his work and very hopeful for the future.

The ten Sections into which the Association is divided include all branches of Science-physical, physiological, and mental-and we try to advance both pure and applied science. For scientific men may be divided into two groups the investigators of theory, and the reducers of theory to practice. The workers in applied science have for their aim the material advancement of the human race. Not only do they bring health to the sick, and an increase of comfort to us all, but they help to make every-day work more interesting to the intelligent, and thus lift the toiler on to a higher level. Also, by increasing the wealth of the world, they give to some men sufficient leisure to pursue pure science or philosophy undisturbed.

On the other hand, the student of pure science-whether he be an astronomer engaged in studying the movements and composition of the starry host, or whether he be a humble entomologist-he, also, has a high object to attain

beyond the facts he so industriously gathers together. Consciously, or unconsciously, he is helping to solve the riddle of the Universe by collecting evidence which may, perhaps, enable us to ascertain the laws which the Creator has imposed upon His work. He is seeking the truth, partly, no doubt, out of curiosity, but partly because he feels that a knowledge of the truth is of the greatest importance to the human race. We can never know the whole truth about the Universe, but we can make an approximation to it; and we may even hope to get some dim idea of why it has been called into existence, and what is the purpose of its Creator. Thus, pure science culminates in a Natural Philosophy. That is, a philosophy built up on an observational basis, which tries to harmonise and explain all observed facts. And this Natural Philosophy must, of course, vary with our knowledge, and get more and more precise as that knowledge increases.*

*

We have lately heard a good deal about the strides made in applied science during the nineteenth century, and we are all agreed as to their importance. In pure science, also, we have heard much of another great feat of the last century, namely, the establishment of the theory of evolution. In this case, all acknowledge its importance, but all are not agreed as to its meaning, and some still think its teaching to be decidedly hurtful. This is a subject to which I have given much thought for the last thirty years, during which time a great change has taken place in scientific opinion, and it is to this change that I wish to direct your attention this evening. It is quite possible that I may have over-estimated the growth of the change; for we, who live in the Southern Hemisphere, are not so advantageously placed for recognising contemporary scientific opinion as those who live nearer the centres of scientific activity. But, whether the change be slow or rapid, it is unquestionably going on, and there can be no doubt about its importance. I am quite aware that the theme I have selected is an But if our ideas are ever to crystallise into some definite shape, it is necessary that a general survey of the position should occasionally be made, and I do not know a better opportunity than the presidential address to an Association like this, where all branches of science are represented. I do not claim to speak with authority, nor do I wish to pose as a philosopher; but I will give you a simple

ambitious one.

• The term

"Natural Philosophy," was formerly limited to the study we now call Physics; but as this use has been altogether abandoned, I hope that I may be allowed to revert to the still earlier and truer meaning of

the term.

statement of the conclusions to which I have been led, and so, I hope, enable each of you to form his own opinion of their value.

THE GROWTH OF NATURAL PHILOSOPHY.

Ever since the dawn of the human intellect, man has tried to increase his knowledge in two ways, by observation and by speculation. Observation came first, for that is common to man and animals. Speculation is a distinctly human attribute, and we find that it soon out-distanced observation, and formed the basis of the earlier philosophies. But, during the last few centuries, the observational method has once more come to the front, under the name of science, and its conclusions have not always been in accord with those of the speculative philosophies which preceded it.

The difference between the two methods is that, whereas speculation starts a chain of reasoning from one or two propositions which are taken as absolutely true, science reasons from the basis of as large a number of observations as possible, and tries to find a hypothesis which connects them all together, or explains them, as it is usually called.

Evidently, this scientific process is a very laborious one, but it is to be more trusted than speculation. For we can never be certain that any single proposition is quite true, or that it contains the whole truth; and, as it is impossible to allow for modifying circumstances, reasoning alone may lead us far astray. While, with the scientific method, attention is directed to errors of observation, which can be corrected, and new facts are constantly confronting us which tend to prove, or to disprove, or to modify, our theories. These theories, in time, get established as what we call "laws of Nature"; that is, accurate records of observed cause and effect, and they thus form a touchstone of exact knowledge by which the speculative philosophies must be tried.

No doubt, these two processes of observation and speculation went on in a desultory, impulsive manner for several thousands of years, during which man not only learnt a great deal about the material world, but was led to speculate about the immaterial, or spiritual, world, which he be lieved to encompass him on all sides. We can never know with certainty how the conception of an invisible, spiritual world arose in the human mind; but we know, as a matter of fact, that it did do so at an early stage of the human intellect. Judging from the beliefs now held by the lowest races of mankind, it seems probable that when man first began, in an incoherent manner, to speculate on himself and his surroundings, the remarkable facts connected with sleep

and dreams made him conclude that his intelligence was due to an unsubstantial body, or spirit, living inside him, which could leave him, travel about. and return. Dreaming of dead friends led him to believe that this spirt lived on as a ghost after the death of the body, and this belief, in time. gave rise to ancestor worship, which passed, first, into the deification of ancestors, and, afterwards, into that of mythical personages who were not considered as ancestors. Thus arose that belief in beneficent tribal gods which still has great influence even among civilised nations.

Primitive man passed from the idea of human spirits to the belief that inanimate bodies also contained spirits. But, as these inanimate things were often thwarting his wishes. and frightening him by noises which he could not understand, he assumed that their spirits were hostile to him, and he tried to appease them by sacrifices, or to disarm them by spells.

The belief that spirits inhabit all kinds of bodies is called Animism. Both it and deification are different forms of Polytheism, which have become so mingled together that it is now often impossible to disentangle them.

This was the natural philosophy of the earlier races of man, and it came to a standstill for want of further knowledge. A very imperfect acquaintance with nature had led to erroneous ideas of religion, and a more accurate acquaintance with nature was not then possible. However, a foundation had been laid which was subsequently built upon by metaphysicians, and, in the course of time, Polytheism passed into what Professor Max Müller has called Henotheism. That is, the gods are no longer regarded as of equa! power, but a supreme spirit rules over the others.

Henotheism appears to have originated independently among the negroes of Africa and the Red Indians of America, as well as among the semi-civilised nations near the eastern shores of the Mediterranean. In Persia and N.W. India, the philosophers developed Animism into Pantheism, a philosophy which teaches that mind pervades all matter, and that nature and God are one. On the other hand, among the Semitic nations, the prophets of Israel gradually passed from a belief in tribal gods to Theism, in which God is recognised as existing outside of, and unconnected with, the material universe, which He has created.

The originators of these philosophies were, however, poets or mystics, who arrived at their conclusions intuitively, and could offer no proofs, thinking, indeed. that their beliefs. must be self-evident to all. So, at a later date, we find an Atheistic philosophy, or Materialism, also, in existence, due,

probably, to a reaction against the excesses of the Greek Mythologists. That the truth of none of these philosophies was self-evident is shown by the fact that, in the classical world, all of them flourished together, and highly cultivated men could be found among the Polytheists, the Pantheists, the Theists, and the Atheists.

At last science awoke from its long sleep, and began to study with care the material phenomena of the Universe.

Scientific observations commenced with the Chaldeans and early Greeks; but it was a dreamy kind of science, confined to a few. The spirit of inquiry was not thoroughly aroused until the bold navigators of the fifteenth and sixteenth centuries sailed round the world, and demolished the old dogma that the earth was a flat disc, with Jerusalem in its centre. Then the invention of the printing press spread the news far and wide, and from that time forwards science took an important position in the world.

Long before this, however, the idea of law and order in Nature had been gradually growing. The wonders of the thunderstorm. of eclipses, even of the rainbow, had been explained as the result of physical laws, and the consequence was that the belief in the crude Polytheism of the ancients had been destroyed.

The advance of scientific knowledge was at first very slow, until, in the seventeenth century, the great improvements which were made in mathematical analysis, as well as the invention of the telescope, enlarged men's ideas enormously. and added vastly to their powers of observation and reasoning. Before the century was over, the size of the earth had been ascertained with tolerable accuracy, and the law of universal gravitation had been discovered. In the eighteenth century, great progress was made in the experimental sciences of physics and chemistry. Electricity was detected, as, also, was oxygen, and this laid the foundation of modern chemistry. Instruments of precision for weighing and measuring were invented, and, at the end of the century, not only was the distance of the sun approximately ascertained, but it was proved that matter was not destroyed when it was burnt, but only rendered invisible. The dis covery that matter was indestructible led, in the nineteenth century, to the further discovery that the physical forces are so correlated that one can be changed into another. And, at last, it was definitely proved that energy was as indestructible as matter; that it was not lost when it was no longer exhibited, but had merely passed into the potential or invisible state.