Blood blood clotting in a transparent container. When blood is drawn in a glass container and left undisturbed for about an hour, four different layers can be seen. A dark clot forms at the bottom (the "black bile"). Above the clot is a layer of red blood cells (the "blood"). Above this is a whitish layer of white blood cells (the "phlegm"). The top layer is clear yellow serum (the "yellow bile"). The ABO blood group system was discovered in the year 1900 by Karl Landsteiner. Jan Janský is credited with the first classification of blood into the four types (A,
Blood, Sweat & Tears Blood, Sweat & Tears Blood, Sweat & Tears is a jazz-rock American music group. They are noted for their combination of brass and rock band instrumentation. The group recorded songs by rock/folk songwriters such as Laura Nyro, James Taylor, The Band and the Rolling Stones as well as Billie Holiday and Erik Satie. They also incorporated music from Thelonious Monk and Sergei Prokofiev into their arrangements. They were originally formed in 1967 in New York City. Since their beginnings, the band has gone through numerous iterations with varying personnel and has encompassed a multitude of musical styles. The band is