C 12 - 3 
II. The Bakerian Lecture . On the Theory of Light and Colours, 
By Thomas Young, M. D . F. R. S. Professor of Natural Phi- 
losophy in the Royal Institution . 
Read November 12, 1801. 
Although the invention of plausible hypotheses, independent 
of any connection with experimental observations, can be of 
very little use in the promotion of natural knowledge ; yet the 
discovery of simple and uniform principles, by which a great 
number of apparently heterogeneous phenomena are reduced 
to coherent and universal laws, must ever be allowed to be of 
considerable importance towards the improvement of the human 
intellect. 
The object of the present dissertation is not so much to pro- 
pose any opinions which are absolutely new, as to refer some 
theories, which have been already advanced, to their original 
inventors, to support them by additional evidence, and to apply 
them to a great number of diversified facts, which have hitherto 
been buried in obscurity. Nor is it absolutely necessary in this 
instance to produce a single new experiment; for of experi- 
ments there is already an ample store, which are so much the 
more unexceptionable, as they must have been conducted with- 
out the least partiality for the system by which they will be 
explained; yet some facts, hitherto unobserved, will be brought 
forwards, in order to show the perfect agreement of that system 
with the multifarious phenomena of nature. 
