‘OCTOBER 6, 1899.] 
of the seventeen hundreds was drawing to- 
wards its end? 
Dover in the year of our Lord seventeen 
’ hundred and ninety-nine was in many ways 
unlike the Dover of to-day. On moonless 
nights men groped their way in its narrow 
streets by the help of swinging lanterns and 
smoky torches, for no lamps lit the ways. 
By day the light of the sun struggled into 
the houses through narrow panes of blurred 
glass. Though the town then, as now, was 
one of the chief portals to and from the 
‘countries beyond the seas, the means of 
travel were scanty and dear, available for 
the most part to the rich alone, and, for 
all, beset with discomfort and risk. Slow 
and uncertain was the carriage of goods, 
and the news of the world outside came to 
the town—though it from its position learnt 
more than most towns—tardily, fitfully, and 
often falsely. The people of Dover sat then 
much in dimness, if not in darkness, and 
lived in large measure on themselves. They 
who study the phenomena of living beings 
tell us that light is the great stimulus of life, 
and that the fullness of the life of a being or 
of any of its members may be measured by 
the variety, the swiftness, and the certainty 
of the means by which it is in touch with its 
surroundings. Judged from this standpoint 
life at Dover then, as indeed elsewhere, must 
have fallen far short of the life of to-day. 
The same study of living beings, however, 
teaches us that while from one point of 
view the environment seems to mould the 
organism, from another point the organism 
seems to be master of its environment. 
‘Going behind the change of circumstances, 
we may raise the question, the old question, 
Was life in its essence worth more then than 
now? Has there been a real advance? 
Let meat once relieve your minds by say- 
ing that I propose to leave this question in 
the main unanswered. It may be, or it may 
not be, that man’s grasp of the beautiful 
and of the good, if not looser, is not firmer 
SCLENCE. 
467 
than it was a hundred years ago. It may 
be, or it may not be, that man is no nearer 
to absolute truth, to seeing things as they 
really are, than he was then. I will merely 
ask you to consider with me for a few 
minutes how far, and in what ways, man’s 
laying hold of that aspect of or part of truth 
which we call natural knowledge, or some- 
times science, differed in 1799 from what it 
is to-day, and whether that change must 
not be accounted a real advance, a real im- 
provement in man. 
I do not propose to weary you by what in 
my hands would be the rash effort of at- 
tempting a survey of all the scientific re- 
sults of the nineteenth century. It will be 
enough if for a little while I dwell on some 
few of the salient features distinguishing 
the way in which we nowadays look upon, 
and during the coming week shall speak of, 
the works of Nature around us—though 
those works themselves, save for the slight 
shifting involved in a secular change, remain 
exatcly the same—from the way in which 
they were looked upon and might have 
been spoken of at a gathering of philoso- 
phers at Dover in 1799. And I ask your 
leave to do so. 
In the philosophy of the ancients, earth, 
fire, air, and water were called ‘the 
elements.’ It was thought, and rightly 
thought, that a knowledge of them and of 
their attributes was a necessary basis of a 
knowledge of the ways of Nature. Trans- 
lated into modern language, a knowledge of 
these ‘ elements’ of old means a knowledge 
of the composition of the atmosphere, of 
water, and of all the other things which we 
call matter, as well as a knowledge of the 
general properties of gases, liquids, and 
solids, and of the nature and effects of com- 
bustion. Of all these things our knowledge 
to-day is large and exact, and, though ever 
enlarging, in some respects complete. When 
did that knowledge begin to become exact ? 
