PRESIDENTIAL ADDRESS. 437 
advantage over Germany; it is important that this should be understood. The 
higher technical instruction across the Rhine has not been undertaken by the 
universities, but is carried out in separate institutions. With us the universities 
have gradually undertaken, in addition to the older technical subjects, theology, 
medicine, and law, the various branches of engineering and agriculture, and even 
commerce. This, it is to be hoped, will be extended so that the highly trained 
technologist may lave the advantage of the undoubted humanising influence of 
the university. 
I have not attempted in this Address any complete survey of chemistry, either 
its growth in the past or its present condition, but I have endeavoured to give 
some account of the sort of thing chemistry is—of its method—and 
Conclusion. to maintain three theses: (1) That the logical method by which 
chemistry advances is not a simple one, and requires as one essential 
element the use of a highly developed imagination. To render this more efficient 
I have advocated special training. (2) Without violating, I hope, the canons 
of the proper use of hypothesis, I have proposed, in order to account for certain 
isomeric and other phenomena, the conception of solid molecular aggregates, 
although I am not able at present to indicate precise methods for its further 
investigation. These molecular aggregates are supposed to be formed by the 
combination of gaseous molecules just as the latter are formed by the combination 
of atoms. (3) As a matter of vital interest to the continued well-being of this 
country I have insisted strongly that our educational resources devoted to 
chemistry should be directed, in the first place and chiefly, to the highest possible 
training of promising students in the prosecution of research, and that the 
giving to the many of elementary instruction should be at least a secondary 
consideration. 
Now, I do not wish to dictate how this last proposition could be best carried 
into effect. I think we should distinguish three classes of chemists, or technical 
chemists, whose domains would more or less overlap. Occasionally there will be 
a man, like the late Sir William Perkin, who would combine all three. The 
three classes are: first, the pure chemist, devoted to scientific discovery only ; 
second, the technical chemist, who prepares the discoveries of the pure chemist 
for the technologist, and has to determine such questions as economical produc- 
tion and, for example, the conversion of colours into dyes; third, the technologist 
or works manager. ‘These three classes should be in close relation to one another. 
By such a scheme we should probably overcome by education one of our most 
serious present difficulties—the ignorance of owners of works of the value of 
science, 
It is a matter deserving most earnest consideration whether, under the pro- 
pitious influence of our own time-spirit, it would be possible to organise research 
and develop it without interfering with its essential freedom and initiative, and 
this in each of the three classes I have mentioned, either by means of some of 
our existing institutions, or by the inauguration here of such an organisation as 
the Kaiser Wilhelm Institut in Berlin. 
The following Papers and Report were then read :— 
1. Interaction between Thiocarbamide, Iodine, and Sulphur. 
By Professor H. Marsuatu, F.R.S. 
2. The Distillation of Binary Miztures of Metals in Vacuo. 
By A. J. Burry, B.A. 
Attempts have been made to isolate inter-metallic compounds in cases where 
one at least of the constituents is volatile by distilling alloys of the two metals 
containing an excess of the more volatile constituent in Jena-glass tubes ex- 
hausted to the highest vacuum. 
The success or failure of this method of isolating inter-metallic compounds 
clearly depends on two factors: (1) The tension of dissociation of the inter- 
metallic compound must be practically nil at the temperature at which the dis- 
tillation is effected; and (2) the partial pressure of the vapour of the more 
volatile constituent must fall abruptly at the composition of the alloy corresponding 
