PRESIDENTIAL ADDRESS. 409 
under which I stand both to the Midland Institute and to the Science and Art 
Department for providing the ladder by which I have risen, however unde- 
servedly, to the honourable position of President of this Section. 
The historian of our times will not fail to note some of the consequences 
which have followed the application of science to industry, possibly also some 
of the educational results which have followed the development of science 
teaching in schools of all grades. Except from one point of view these need not 
concern us now, as they fall, the one in so far as Chemistry is concerned, into the 
province of the Society of Chemical Industry, the other mainly within the 
purview of Section L. This bringing of Chemistry to the people has aroused a 
widespread interest in some aspects of the subject, of which the Press has not 
been slow to take note. Not even the heuristic method can hide from the school- 
boy the fact that certain fundamental conceptions are accepted which do not 
admit of proof, such as the indivisible atom, the non-decomposable element, the 
indestructibility of matter. When, therefore, as one of the first-fruits of his 
discovery that positive rays furnish the most delicate method of chemical 
analysis, Sir J. J. Thomson has obtained from the most diverse solids a new 
gas, X,; and by a different procedure, Professor Collie with Mr. Patterson have 
discovered that hydrogen, under the influence of electric discharges at low 
pressure, becomes replaced by neon, helium, and a third gas which is possibly 
identical with X,,° it is not surprising that we should hear much about it in the 
newspapers, just as was the case when the disintegration of radium was in process 
of being established. Further investigation may fail to substantiate some of 
the views which have been expressed about this unexplained disappearance of 
hydrogen; the origin of the neon and helium which make their appearance in 
the tube as the experiments proceed; the source of the gas X,. Fortunately 
X,, unlike neon and helium, has some chemical properties—it disappears, for 
example, when violently exploded with a mixture of oxygen and hydrogen—but 
we do not yet know whether it is a new element with an atomic weight of about 3, 
or a compound of hydrogen with an element yet to be discovered. This much 
at least seems certain; it is not the gas which, according to Mendeléef, should 
precede fluorine in the halogen series, but whether its discovery, like that of 
argon, will necessitate a revision of the Periodic table of the elements we 
cannot know until the mystery which at present surrounds it has been dispelled. 
It was in 1886, at the last meeting of this Association in Birmingham, that 
Sir William Crookes—whose continued activities are a source of pride and 
gratification to his brother chemists—gave that famous address in which, 
clothing his ideas in language which has something of the magic of word-paint- 
ing, he traced the evolution of the elements, as we know them, from the 
hypothetical protyle or Urstoff. The common origin of all elementary sub- 
stances is now an accepted theory, although the question whether the idea under- 
lying the term ‘transmutation ’ is verifiable under available conditions is answered 
differently according to the view we take of the disintegration of radium and 
kindred phenomena. But no one could have imagined that before another 
Birmingham meeting, the Periodic table to which Sir William Crookes devoted 
much attention would have been enriched not only by a series of elements devoid 
of chemical properties, but by a second series, known only in minute quantities, 
and displaying those extraordinary properties of radio-activity which have 
revolutionised our ideas in more than one direction. 
It is not necessary for me to chronicle even the more striking achievements 
in chemistry since 1886; a few examples will show how great the progress has 
been. It is on record that Arrhenius was present at that meeting, but his 
advocacy of that theory of solution with which his name will always be 
asscciated came a little later; phenylhydrazine, which was to play so important a 
part in Emil Fischer’s investigation of the sugars, had been discovered by him 
only two years previously; the Grignard reagent, which in other directions has 
played a no less important part in synthetical organic chemistry, did not become 
available until some fourteen years later. Theories then emerging, such as that 
2J. N. Collie and H. S. Patterson, 7'rans. Chem. Soc., 1913, 108, 419; Proc. 
Chem. Soc., 1913, 29, 217. 
3 Sir J, J. Thomson, Proc. Roy. Soc., 1913, 894, 20. 
