Quote by Dmitri Mendeleev

"The periodic law is the only quantitative law of chemistry which is capable of being generally applied."

"I saw in the dream the table of elements arranged in accordance with their atomic weights, and when I awoke, I immediately wrote it down on a piece of paper."

"If you wish to become a philosopher, learn to ask pertinent questions."

"A man must believe in something."

"Never underestimate the power of a good laugh."

"Laughter is the best medicine."

"A good laugh is the best medicine."

"Laughter is contagious and wonderful."