"I am not afraid of failure, for it is through failure that we learn."

"I am busy just now again on the old subject of light and experiment, and hope to have some new views to bring out."

"I have in fact been a very lucky fellow; I have often said that I should be a very miserable creature if I could not feel that I was doing something for the good of other people."

"The greatest error is to believe that one knows everything."

"But still try, for who knows what is possible?"