Photo source: Wikimedia Commons
Dmitri Mendeleev (1834-1907) was a Russian chemist best known for creating the first version of the periodic table of elements. David Sang, Lawrie Ryan and Jane Taylor said,
"Dmitri was writing a textbook and wanted to organized the elements properly. So he wrote each element onto its own card to help him sort them out.... one evening dosed off while working. He had a dream in which each of the cards lined up in rows, just like a game of patience. When he work, he realized that he should put the elements in order of atomic mass." (Scientifica: Raiders of the Lost Quadrat, 2005)Anna and Patrick Fullick said,
"[Mendeleev's] stroke of genius was to leave gaps for elements that were still to be discovered, predicting what their properties should be from his table." (Chemistry for AQA Co-Ordinated Award, 2001)The rest of this post is a some quotes from Mendeleev.
Periodic table
"I saw in a dream a table where all the elements fell into place as required. Awakening, I immediately wrote it down." (AZquotes.com)
"I wish to establish some sort of system not guided by chance, but by some sort of definite and exact principle." (An Outline of the System of Elements)
"I suppose when my unknown elements are found, more people will pay us attention." (An Outline of the System of Elements)
Elements
"We should still expect to discover many unknown simple bodies; for example, those similar to aluminum and silicon, elements with atomic weights of 65 to 75." (An Outline of the System of Elements)
"The elements which are the most widely diffused have small atomic weights." (AZquotes.com)
"The magnitude of the atomic weight determines the character of the element, just as the magnitude determines the character of a compound body." (Brainyquote.com)
Laws of nature
"It is the function of science to discover the existence of a general reign of order in nature and to find the causes governing this order." (AZquotes.com)
"We could live at the present day without a Plato, but a double number of Newtons is required to discover the secrets of nature, and to bring life into harmony with the laws of nature." (Brainyquote.com)
"No law of nature, however general has been established all at once; its recognition has always been preceded by many presentiments." (AZquotes.com)