9 
whose experimental researches in electricity must be regarded as 
the finest example of inductive investigation to be found in the 
annals of British science, and the most perfect exemplification 
of the philosophy of Bacon to which the student in physics can 
be referred, has proved that a single drop of water holds impri- 
soned in its liquid chains a quantity of electricity which equals 
that contained in an ordinary thunder-cloud. In every form of 
the voltaic battery a very large quantity of electricity is lost in 
passing from the liquid to the solid element, and the contrary ; 
so that in overcoming the resistance nearly three fourths of 
the power is consumed. 
Allow me to give another example of the value of close 
observation in connexion with magnetism. Dr. Faraday was 
the discoverer of the fact, that when a hollow helix of copper 
wire containing - a core of soft iron was moved in front of or 
near the poles of a permanent steel magnet, electricity was 
evolved, and all the results of voltaism readily produced. Hence 
the formation of magneto-electrical machines ; and in the great 
electro-plating establishments of Birmingham we may see the 
process carried on by the current thus generated by the 
revolution of coils of copper wire placed on an iron armature 
near the poles of an ordinary steel magnet. 
To the true philosopher everything, howsoever insignificant 
to ordinary minds, is felt to deserve attention, and the minutest 
phenomena claim the most accurate study. A body falls to the 
ground, — a drop of water hanging from a rod, or resting on a 
leaf, assumes a spherical form. Nature is asked, Why is this? 
and the answer is the discovery of the law of gravitation, by 
which power each planet is retained in its orbitual path around 
the sun, and the entire solar system, held as completely in 
union as the particles of the water-drop, moved through space 
under the influence of a gravitating force resident in some far 
distant and probably unseen star. Reflection on the discovery 
of the planet Neptune must lead to the conviction of the truth 
of the Newtonian law of gravitation. 
Up to the year 1804 the planet Uranus moved in its orbit 
without any appearance of disturbing influences ; but at that 
period an accelerated motion became evident, and this con- 
