ee ae 
DISCOVERIES BECOME FAMILIAR. 437 
feel it easier to bear with injustice, than to struggle for 
redress. And as to considerations of pecuniary interest, 
they are of no value in my estimation. Besides which, 
my future depends on the encouragement that the public 
may be inclined to grant me, and not at all on that of 
Mr. Cavendish or of his friends.” 
Ought I to fear, that I have attached too much im- 
portance to the theory that Watt imagined for explain- 
ing Priestley’s experiments? I think not. Those who 
would refuse a rational consent to this theory, because it 
‘now seems the inevitable result of facts, must forget that 
the finest discoveries achieved by the human mind have 
been, above all, remarkable for their simplicity. What 
did Newton* himself do, when, repeating an experiment 
that had been known already for fifteen centuries, he dis- 
covered white light? He gave so natural an interpreta- 
tion of this experiment, that it now seems impossible to 
offer any other; he says—*“ Al] that is obtained, by any 
proceeding whatever, from a pencil of white light, must 
have been contained in it in a state of mixture. The 
glass prism possesses no creative property. If the paral- 
* This is barely in point; some of the phenomena of colours were 
certainly known before the advent of Newton, but that princeps philos- 
ophorum formed the prismatic spectrum itself, by which the spaces 
occupied by the successive colours were accurately defined, the 
colours submitted to a similar analysis, and the white light re-formed; 
thus ascertaining and proving that light, instead of being homoge- 
neous as had been supposed, was actually a heterogeneous mixture 
of differently refrangible rays. Nor do we quite quadrate with the 
lengthy discussion before us, since we do not consider the case—in ré 
the beautiful composition of water—to be conclusively established. 
To those readers who are interested in so crucial a point in scientific 
history, we recommend a perusal of Vernon Harcourt’s remarkable 
address to the British Association at Birmingham, in 1839; it being 
alike free from reckless assertion, and that hot nationality which 
warps judgment.— Translator. 
