History
The phenomenon was first noticed over one hundred years ago (in 1896) by the German chemist Raphael E. Liesegang, and has aroused the curiosity of chemists for many years. It was first noted when he dropped a solution of silver nitrate on to a thin layer of gel containing potassium dichromate. After a few hours, sharp concentric rings of insoluble silver dichromate formed. When formed in a test tube by diffusing one component from the top, layers or bands of precipitate form, rather than rings.
Read more about this topic: Liesegang Rings
Famous quotes containing the word history:
“No event in American history is more misunderstood than the Vietnam War. It was misreported then, and it is misremembered now.”
—Richard M. Nixon (b. 1913)
“The history of modern art is also the history of the progressive loss of art’s audience. Art has increasingly become the concern of the artist and the bafflement of the public.”
—Henry Geldzahler (1935–1994)
“Free from public debt, at peace with all the world, and with no complicated interests to consult in our intercourse with foreign powers, the present may be hailed as the epoch in our history the most favorable for the settlement of those principles in our domestic policy which shall be best calculated to give stability to our Republic and secure the blessings of freedom to our citizens.”
—Andrew Jackson (1767–1845)