In 1827, French physician Alfred Velpeau autopsied the body of a man who had experienced fever, weakness, pain, pus-filled blood, and headaches, and whose spleen weighed 10 lb (4.5 kg). Twelve years later, two more French physicians reported similar cases of fever, weakness, and enlarged organs, but suggested that the "pus-filled blood" actually contained white blood cells, or leukocytes. Scottish physicians found leukocytes when they conducted several more autopsies in 1845, including a man whose liver and spleen weighed 11 lb (4.9 kg) and 8 lb (3.6 kg), respectively. Also in 1845, German pathologist Rudolph Virchow coined a new term, weisses blut (white blood) to describe an imbalance between leukocytes and red blood cells, or erythrocytes. In 1890, another German physician, Paul Ehrlich, discovered that leukocytes varied by shape, kind, and function. In 1910, the same year that he discovered Salvarsan, the first "magic bullet" used against syphilis, Ehrlich discovered the poisonous extracts of mustard plants that were eventually developed into the first biological weapons. When inhaled, these "mustard gases" badly damaged lymph glands and the bone marrow, where white blood cells originate.
The French physicist Pierre Curie had weakness and swollen organs and glands until he was killed in 1906 by a horse-drawn carriage. In 1903, he and his Polish wife, Marie Curie (along with Henri Becquerel) shared the Nobel Prize in Physics. Following her discovery of the highly radioactive materials radium and polonium (she coined the term "radioactivity"), Marie Curie pioneered the battlefield use of primitive x-ray machines (protected only by fabric gloves and a thin metal screen) to locate bullets and shrapnel in wounded soldiers. Curie died in 1934 after experiencing the same pain and headaches, fatigue, swollen glands and organs—as did her daughter and son-in-law. Neither scientist linked his or her symptoms to the burns they experienced with each exposure to radium.
When Velpeau first peered through his microscope in 1827 at his "globules of pus in the blood," he was actually seeing leukemia, a disease name given by Virchow in 1847. The fevers, headaches, engorged glands, and swollen organs that those French, German and Scottish patients had developed, and the cause of Marie Curie's death, were leukemia. The disease that the American researchers were trying in 1942 to treat with highly toxic chemical therapies (nitrogen mustard), in extension of Ehrlich's earlier work with mustard plant extracts, was also leukemia.