Statue to Sir Isaac Newton. 47 
erties of an acid (chlorine) is found to have no oxygen at all, 
while many substances abounding in oxygen, including alkalies 
themselves, have no acid property whatever; and without the 
access of oxygenous or of any other gas heat and flame are pro- 
uced in excess. 
The doctrines of free trade had not long been promulgated 
by Smith before Bentham demonstrated that his exception of . 
usury was groundless; and his theory has been repeatedly 
proved erroneous on colonial establishments, as well as his ex- 
ception to it on the navigation laws; and the imperfection of his 
views on the nature of rent is undeniable, as well as on the 
principle of population. In these and such instances as these it 
would not be easy to find in the original doctrines the means of 
correcting subsequent errors, or the germs of extended discovery. 
But even if philosophers finally adopt the undulatory theory of 
light instead of the atomic, it must be borne in. mind that New- 
ton gave the first elements of it by the well known proposition 
in the 8th section of the Second Book of the Principia, the 
scholium to that section also indicating his expectation that it 
would be applied to optical science; while Biot has shown 
how the doctrine of fits of reflection and transmission tallies 
tants of the old cast their eyes over lands and seas far distant 
m those he had traversed; lands and seas of which they could. : 
form to themselves no conception, any more than they had been 
able to comprehend the course by which he Jed them on his 
grand enterprise. In this achievement, and in the qualities 
which alone made it possible, inexhaustible fertility of resources, 
patience unsubdued, close meditation that would suffer no dis- 
traction, steady determination to pursue paths that seemed all 
but hopeless, and unflinching courage to declare the truths they 
led to, how far soever removed from ordinary apprehension—in 
