Keith Houston on brief history of the Octothorpe (#), Pilcrow (¶), manicule (☞), and other unusual punctuation marks: http://nyr.kr/15BYowC
Left, from the pen of Isaac Newton; right, detail from Johann Conrad Barchusen’s “Pyrosophia” (1698). Courtesy the Othmer Library of Chemical History, Chemical Heritage Foundation.
Excerpt from a page from Villanova University’s “Rudimenta Grammaticæ” (1500). Courtesy Wikimedia Commons.
In Classic Chinese, there were no punctuation, instead, certain Chinese characters are used as punctuation. So if we see these characters, we know if it is a question sentence or a statement. Later on, they put black dot as a period. That periods is when people printed books and read it from right to left vertically. And much later after PRC was founded, we developed a new system, including using a circle as period, comma, and all the other western punctuations.