734 REPORT—1896. 
Section B.—CHEMISTRY. 
PRESIDENT OF THE SEcTION.—Dr. Lupwie Monp, F.R.S. 
THURSDAY, SEPTEMBER 1i. 
The President delivered the following Address :— 
Iy endeavouring to fix upon a suitable theme for the address I knew you 
would to-day expect from me, I have felt that I ought to give due consideration 
to the interests which tie this magnificent city of Liverpool, whose hospitality we 
enjoy this week, to Section B of the British Association. 
I have therefore chosen to give you a brief history of the manufacture of 
chlorine, with the progress of which this city and its neighbourhood have been 
very conspicuously and very honourably connected, not only as regards quantity— 
I believe this neighbourhood produces to-day nearly as much chlorine as the rest 
of this world together—but more particularly by having originated, worked out, 
and carried into practice several of the most important improvements ever intro- 
duced into this manufacture. I was confirmed in my choice by the fact that this 
manufacture has been influenced and perfected in an extraordinary degree by the 
rapid assimilation and application of the results of purely scientific investigations 
and of new scientific theories, and offers a very remarkable example of the 
incalculable value to our commercial interests of the progress of pure science. 
The early history of chlorine is particularly interesting, as it played a most 
important rdle in the development of chemical theories. There can be no doubt 
that the Arabian alchemist Geber, who lived eleven hundred years ago, must have 
known that ‘Aqua Regia,’ which he prepared by distilling a mixture of salt, 
nitre, and vitriol, gave off on heating very corrosive, evil-smelling, greenish- 
yellow fumes, and all his followers throughout a thousand years must have been 
more or less molested by these fumes whenever they used Aqua Regia, the one 
solvent of the gold they attempted so persistently to produce. 
But it was not until 1774 that the great Swedish chemist Scheele succeeded 
in establishing the character of these fumes. He discovered that on heating 
manganese with muriatic acid he obtained fumes very similar to those given off 
by ‘Aqua Regia, and found that these fumes constituted a permanent gas of 
yellowish-green colour, very pungent odour, very corrosive, very irritating to the 
respiratory organs, and which had the power of destroying organic colouring 
matters. 
According to the views prevalent at the time, Scheele considered that the 
manganese had removed phlogiston from the muriatic acid, and he consequently 
called the gas dephlogisticated muriatic acid. 
When during the next decade Lavoisier successfully attacked, and after a 
memorable struggle completely upset, the phlogiston theory and laid the founda- 
tions of our modern chemistry, Berthollet, the eminent ‘father’ of physical 
