Dmitri Mendeleev presented his periodic table of the elements based on increasing atomic weight on March 6, 1869, in a presentation to the Russian Chemical Society. While Mendeleev's table was the first to gain some acceptance in the scientific community, it was not the first table of its kind.
In the end, the British sale of opium was used as means for  obtaining more land and trading rights from the Chinese, leading to  the devastation of the Chinese government and economy which is why  The First Opium War will be remembered in history as the time when  China was ultimately betrayed by the British.
A: The Opium War opened China up to foreign trade for the first time, but also threatened the stability of the Manchu government and made China a center for illegal activity. The conflict actually had two phases, from 1839 to 1842 and again from 1856 to 1860, pitting the Qing rule in China against the British Empire.