PRESIDENTIAL ADDRESS. ink. 
fascination, either in this theory itself, or in its authors, that 
commanded the loyalty of these exceptionally shrewd men. 
It fell to the lot of Lavoisier, of tragic memory, to throw 
off the spell of this theory, and to supply the true interpreta 
tion of the resulis obtained by these scientists... No one 
need grudge him this honour. The building was raised 
especially by Black, and Priestley, and Scheele, and Caven- 
dish, but Lavoisier, by decisive experiment and lucid expla- 
nation, opened it to the world. 
Over and above their genius, their strength lay in the 
beautiful spirit of research with which they were all im- 
bued, and in the rigid experimental methods adopted. I 
picture them as engaged in threading the same intricate 
maze (nature may be regarded as a complicated labyrinth), 
but, instead of moving to and fro at random, as so many of 
their predecessors had done, they settled down to systematic 
examination, surveying and plotting and mapping out the 
puzzle step by step, each blind passage marked so as to 
save traversing it again, all working at different places, per- 
haps, but all with the same end in view; and the plans of 
each one’s work published—open to all. This is scientific 
work. It was only a question of time when all these parts 
would piece together, and the final passage be disclosed. 
And this is doubtless true for all future work, and may well 
encourage the humblest scientific worker. 
IMMEDIATE RESULTS. 
The series of investigations ending with the briliiant ex- 
perimental work and interpretatiofs of Cavendish and of 
Lavoisier conclude the first part of the solution of the 
mystery of the air. The demonstrations referred to entirely 
justified the conclusion that atmospheric air was, in the 
main, a mixture of oxygen and nitrogen in more or less con- 
stant proportion, together with carbon dioxide, vapour of 
water, and, according to Scheele, a trace of ammonia. Allk 
these investigators. however, were perfectly persuaded that 
the composition of the air was much more complicated. 
The science thus born began to grow apace, and occupied 
itself with great enthusiasm in tracing these discoveries out 
to their consequences. These consequences were stupendous. 
New branches of science appeared. - The new ideas stirred 
every known science to its foundations, and, indeed, brought 
for each a new birth. To follow these inquiries out would 
be to write a history of chemistry and its applications; even 
in confining our attention to those on which the chemistry of 
