eam was
turned into motive power by first-rate steam engines, and the motive
power converted into electricity by a dynamo, the yield of electricity
would in the most favorable case not exceed 8 per cent. of the energy
in the gas. I hope that this kind of battery will one day enable us to
perform chemical operations by electricity on the largest scale, and
to press this potent power into the service of the chemical
industries.

The statement is frequently made that "Necessity is the mother of
invention." If this has been the case in the past, I think it is no
longer so in our days, since science has made us acquainted with the
correlation of forces, teaching us what amount of energy we utilize
and how much we waste in our various methods for attaining certain
objects, and indicating to us where and in what direction and how far
improvement is possible; and since the increase in our knowledge of
the properties of matter enables us to form an opinion beforehand as
to the substances we have available for obtaining a desired result.

We can now foresee, in most cases, in what direction progress in
technology will move, and in consequence the inventor is now
frequently in advance of the wants of his time. He may even create new
wants, to my mind a distinct step in the development of human culture.
It can then no longer be stated that "Necessity is the mother of
invention;" but I think it may truly be said that the steady,
methodical investigation of natural phenomena is the father of
industrial progress.

Sir Lowthian Bell, Bart., F.R.S., in moving a vote of thanks, said
that the meeting had had the privilege of listening to a description
of results obtained by a man of exceptional intelligence and learning,
supplemented by that devotion of mind which qualified him to pursue
his work with great energy and perseverance. The importance of the
president's address could not possibly be overrated. At various
periods different substances had been put forward as indications of
the civilization of the people. He remembered hearing from Dr. Ure
that he considered the consumption of sulphuric acid to be the most
accurate measure of the civilization of the people.

In course of time sulphuric acid gave way to soap, the consumption of
which was probably still regarded as the great exponent of
civilization by such of his fellow citizens as had thereby made their
name. From what he had heard that morning, however, he should be
inclin