1861 introductions

Thallium is a chemical element; it has symbol Tl and atomic number 81. It is a silvery-white post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861, in residues of sulfuric acid production. Both used the newly developed method of flame spectroscopy, in which thallium produces a notable green spectral line. Thallium, from Greek , , meaning "green shoot" or "twig", was named by Crookes. It was isolated by both Lamy and Crookes in 18

additive color model based on combining red, green, and blue

1860s multi-barrel rapid-fire gun of Richard Gatling, or its 1880s-1890s variants

organic eponymous reaction of silver salts of carboxylic acids with halogens to give organic halides.

streetcar network in Ontario, Canada

head of state and of government of the Confederate States

was a after ''Man'en and before Genji''. This period spanned the years from March 1861 through March 1864. The reigning emperor was .

board game

current denomination of United States currency

blended in Scotland, UK

denomination of US currency, recalled in 1969

British biscuit consisting of currants squashed and sandwiched between two thin oblongs of biscuit dough before baking

bank bill

denomination of US currency