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, toil, tears, and sweat The motion passed unanimously. This was the first of three speeches which he gave during the period of the Battle of France, which commenced on 10 May. Churchill had used similar phrases earlier, such as "Their sweat, their tears, their blood" in 1931, and "new structures of national life erected upon blood, sweat, and tears". Churchill's sentence, "I have nothing to offer but blood, toil, tears, and sweat," has been called a paraphrase of one uttered on 2 July 1849 by Giuseppe Garibaldi when rallying his revolutionary forces in Rome: "I offer hunger, thirst, forced marches, battle, and death." As