As Virchow was uncertain of the cause of the white blood cell excess, he used the purely descriptive term leukemia (Greek: white blood) to refer to the condition. Further advances in the understanding of acute myeloid leukemia occurred rapidly with the development of new technology. In 1877, Paul Ehrlich developed a technique of staining blood films which allowed him to describe in detail normal and abnormal white blood cells. Wilhelm Ebstein introduced the term ''acute leukemia'' in 1889 to differentiate rapidly progressive and fatal leukemias from the more indolent chronic leukemias.
The flag was designed by Andrew Carlisle Johnson in 1911 and adopted by the Colorado General Assembly on June 5 of the same year. However, the legislature did not specify the size of the C or the exact shade of blue or red.n a 2001 survey of 72 state, provincial, and territorial flags conducted by the North American Vexillological Association, Colorado's flag was ranked number 16.
Colorado is nicknamed the Centennial State because it entered the union in 1876, 100 years after the signing of the Declaration of Independence. This nickname is a reference to the quantities of silver that have been mined in Colorado. Leadville became one of the world's greatest mining camps in 1878.