‘OCTOBER 6, 1899. ] 
read the scientific literature of the time to 
recognize that a truth which is now not only 
woven as a master-thread into all our scien- 
tific conceptions, but even enters largely into 
the everyday talk and thoughts of educated 
people, was a hundred years ago struggling 
into existence among the philosophers them- 
selves. It was all but absolutely unknown 
to. the large world outside those select few. 
If there be one word of science which is 
writ large on the life of the present time, it 
is the word ‘electricity’; it is, I take it, 
writ larger than any other word. The 
knowledge which it denotes has carried its 
practical results far and wide into our daily 
' life, while the theoretical conceptions which 
it signifies pierce deep into the nature of 
things. We are to-day proud, and justly 
proud, both of the material triumphs and of 
the intellectual gains which it has brought 
us, and we are full of even larger hopes of 
it in the future. 
At what time did this bright child of the 
nineteenth century have its birth? 
He who listened to the small group of 
philosophers of Dover, who in 1799 might 
have discoursed of natural knowledge would 
perhaps have heard much of electric ma- 
chines, of electric sparks, of the electric 
fluid, and even of positive and negative 
electricity; for frictional electricity had 
long been known and even carefully studied. 
Probably one or more of the group, dwell- 
ing on the observations which Galvani, an 
Italian, had made known some twenty 
years before, developed views on the con- 
nection of electricity with the phenomena 
of living bodies. Possibly one of them was 
exciting the rest by telling how he had just 
heard that a professor at Pavia, one Volta, 
had discovered that electricity could be 
produced not only by rubbing together par- 
ticular bodies, but by the simple contact of 
two metals, and had thereby explained Gal- 
vani’s remarkable results, For, indeed, as 
SCIENCE. 
469 
we shall hear from Professor Fleming, it was 
in that very year, 1799, that electricity as 
we now know it took its birth. It was then 
that Volta brought to light the apparently 
simple truths out of which so much has 
sprung. The world, itis true, had to wait for 
yet some twenty years before both the prac- 
tical and the theoretic worth of Volta’s dis- 
covery became truly pregnant, under the 
fertilizing influence of another discovery. 
The loadstone and magnetic virtues had, 
like the electrifying power of rubbed am- 
ber, long been an old story. But, save for 
the compass, not much had come from it. 
And even Volta’s discovery might have 
long remained relatively barren had it been 
left to itself. When, however, in 1819, 
Oersted made known his remarkable ob- 
servations on the relations of electricity to 
magnetism, he made the contact needed for 
the flow of a new current of ideas. And it 
is perhaps not too much to say that those 
ideas, developing during the years of the 
rest of the century with an ever-accelera- 
ting swiftness, have wholly changed man’s 
material relations to the circumstances of 
life, and at the same time carried him far 
in his knowledge of the nature of things. 
Of all the various branches of science, 
none perhaps is to-day, none for these many 
years past has been, so well known to, even 
if not understood by, most people as that 
of geology. Its practical lessons have 
brought wealth to many; its fairy tales 
have brought delight to more; and round 
it hovers the charm of danger, for the con- 
clusions to which it needs touch on the na- 
ture of man’s beginning. 
In 1799, the science of geology, as we now 
know it, was struggling into birth. There 
had been from of old cosmogonies, theories 
as to how the world had taken shape out 
of primeval chaos. In that fresh spirit 
which marked the zealous search after 
natural knowledge pursued in the middle 
