ADDRESS. 7 
with metals during calcination’ appeared in 1775, and Cavendish’s paper 
on the composition of water did not see the light until 1784. 
During the last quarter of the eighteenth century this new idea of 
oxygen and oxidation was struggling into existence. How new was the 
idea is illustrated by the fact that Lavoisier himself at first spoke of that 
which he was afterwards, namely in 1778, led to call oxygen, the name by 
which it has since been known, as ‘the principle which enters into combina- 
tion.’ What difficulties its acceptance met with is illustrated by the 
fact that Priestley himself refused to the end of his life to grasp the 
true bearings of the discovery which he had made. In the year 
1799 the knowledge of oxygen, of the nature of water and of air, and 
indeed the true conception of chemical composition and chemical 
change, was hardly more than beginning to be, and the century had to 
pass wholly away before the next great chemical idea, which we know by the 
name of the Atomic Theory of John Dalton, was made known. We have 
only to read the scientific literature of the time to recognise that a truth 
which is now not only wovenas a master-thread into all our scientific con- 
ceptions, but even enters largely into the everyday talk and thoughts of 
educated people, was a hundred years ago struggling into existence 
among the philosophers themselves. 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 intel- 
lectual 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 machines, 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, dwelling on the observations which Galvani, an Italian, had 
made known some twenty years before, developed views on the connection 
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 particular bodies, but by the simple contact 
of two metals, and had thereby explained Galvani’s remarkable results. 
For, indeed, as we shall hear from Professor Fleming, it was in that 
