Such is the beautiful theory of Fresnel and Young, for we must not, in our regard for one great name, forget the justice which is due to the other; and to separate them, and to assign to each his share, would be as impracticable as invidious, so intimately are they blended together throughout every part of this system--early, acute, and pregnant suggestion characterising the one, and maturity of thought, fulness of systematic development, and decisive experimental illustration equally distinguishing the other. During the last five years of Dr. Young’s life, when he was between fifty-one and fifty-six years old, he ceased to be a practising physician, and occupied himself with science and literature only. In 1827, at the anniversary of the Royal Society, after the resignation of the presidency by Sir Humphry Davy, the claims of Dr. Young were too strong to be altogether neglected. Writing to his sister he says: I find there has been pretty general conversation about making me President of the Royal Society, and I really think if I were foolish enough to wish for the office, I am at this _moment_ popular enough to obtain it; but you well know that nothing is further from my wishes. Davies Gilbert was chosen. ‘I told him,’ says Young, ‘that he had not quite enough of the devil in him, that Sir Joseph Banks should have left his _eyebrows_ to go with his cocked hat, if he had left the Society nothing else.’ In the summer of 1828 he visited Paris for the last time on his way to Geneva. He was then one of the eight foreign associates of the Academy. To Mr. Gurney he wrote: My principal object was Champollion, and with him I have been completely successful as far as I wanted his _assistance_, for, to say the truth, our conferences have not been very gratifying to my _vanity_. He has done so much more and so much better than I had any reason to believe he would or could have done, and, as he feels his own importance more, he feels less occasion to be tenacious of any trifling claims which may justly be denied him, and in this spirit he has borne my criticisms with perfect good humour, though Arago has charged me with some degree of undue severity, and wanted to pass the matter over as not having been published as mine; but to this I could not consent: and, supposing that Champollion might have been unacquainted with the remarks, I thought it a matter of conscience to carry them to him this morning, before I allowed him to continue his profuse liberality in furnishing me with more than I want.