2 
that he discovered Fluxions in 1665-6, the Unequal Refran- 
gibility of Light in 1666, the Reflecting Telescope in 1668, 
and published the Principia in 1687 ; and that with that 
publication, which Whewell has designated “ The Great 
Charter of Modern Science,” his career, as an original dis- 
coverer, appears to have terminated. He quoted passages 
from Mr. Edleston’s Correspondence of Newton and Cotes, 
and from Sir David Brewster’s larger Life of Newton, to show 
that his appointment to the Mint, in a great measure, stopped 
further researches. “ Henceforward,” says Mr. Edleston, 
“his official duties rendered it impossible for him to work 
continuously at his former pursuits; and his studies in 
mathematics and natural philosophy were by snatches, and 
in the intervals of business.” “ His duties at the Mint,” 
says Sir David, “ allowed him but little time for the perform- 
ance of so laborious a task as 'the publication of a second 
edition of the Principia , and when his consent was at last 
obtained to put the work to the press, they greatly interrupted 
its progress ? ” Again, in one of his letters to Flamstead, he 
says that he did not like to be known to be attending to any- 
thing but the King’s business, meaning the duties of the 
Mint. Therefore, after the publication of the Principia , he 
may be practically regarded as a retired philosopher. 
The writer then attempted to show that the current por- 
traits of Newton do not give us any correct representation of 
Newton, the philosopher. He exhibited various engravings 
of Newton. He pointed out that Yertue’s print, after Yan- 
derbank, is inscribed “Isaacus Newtonus Eq. Aui\ set. 83. 
J. Yanderbank pinxit 1725, Geo. Yertue sculpsit 1726;” 
and, therefore, that the date of that celebrated picture, in 
possession of the Royal Society, represents him in extreme 
old age. This picture, therefore, he contended, was not a 
portrait of the great Newton, but of Newton the Master of 
the Mint, who assayed Wood’s halfpence ; and that it could 
not, for one moment, be accepted as a representation of 
