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.
It consisted of the First Opium War from 1839 to 1842 and the Second Opium War from 1856 to 1860. Opium, which was not prohibited in the United Kingdom of Great Britain and Ireland, was smuggled by merchants from British India into China in defiance of Chinese prohibition laws.